Falco Rules Overview

Last Updated: 2024-10-23

This auto-generated document is derived from the falco*_rules.yaml files within the rules directory of the main branch in the official Falco rules repository.

The Falco Project manages a total of 89 rules, of which 25 rules are included in the Falco release package and labeled with maturity_stable. Rules at the remaining maturity levels require explicit installation and may need extra customization to ensure effective adoption. Lastly, certain rules are intentionally disabled by default, irrespective of their maturity level.

This document provides an extensive overview of community-contributed syscall and container event-based rules. It offers resources for learning about these rules, promoting successful adoption, and driving future enhancements.

Stable Falco Rules | Incubating Falco Rules | Sandbox Falco Rules | Deprecated Falco Rules | Falco Rules Stats

The tables below can be scrolled to the right.

Stable Falco Rules

25 stable Falco rules (28.09% of rules) are included in the Falco release package:

maturity	rule	desc	workload	mitre_phase	mitre_ttp	extra_tags	compliance_pci_dss	compliance_nist	enabled
maturity_stable	Clear Log Activities	Detect clearing of critical access log files, typically done to erase evidence that could be attributed to an adversary's actions. To effectively customize and operationalize this detection, check for potentially missing log file destinations relevant to your environment, and adjust the profiled containers you wish not to be alerted on.	container, host	mitre_defense_evasion	T1070	filesystem		NIST_800-53_AU-10	True
maturity_stable	Contact K8S API Server From Container	Detect attempts to communicate with the K8S API Server from a container by non-profiled users. Kubernetes APIs play a pivotal role in configuring the cluster management lifecycle. Detecting potential unauthorized access to the API server is of utmost importance. Audit your complete infrastructure and pinpoint any potential machines from which the API server might be accessible based on your network layout. If Falco can't operate on all these machines, consider analyzing the Kubernetes audit logs (typically drained from control nodes, and Falco offers a k8saudit plugin) as an additional data source for detections within the control plane.	container	mitre_discovery	T1565	network, k8s			True
maturity_stable	Create Hardlink Over Sensitive Files	Detect hardlink created over a curated list of sensitive files or subdirectories under /etc/ or root directories. Can be customized as needed. Refer to further and equivalent guidance within the rule "Read sensitive file untrusted".	container, host	mitre_credential_access	T1555	filesystem			True
maturity_stable	Create Symlink Over Sensitive Files	Detect symlinks created over a curated list of sensitive files or subdirectories under /etc/ or root directories. Can be customized as needed. Refer to further and equivalent guidance within the rule "Read sensitive file untrusted".	container, host	mitre_credential_access	T1555	filesystem			True
maturity_stable	Debugfs Launched in Privileged Container	Detect file system debugger debugfs launched inside a privileged container which might lead to container escape. This rule has a more narrow scope.	container	mitre_privilege_escalation	T1611	cis, process			True
maturity_stable	Detect release_agent File Container Escapes	Detect an attempt to exploit a container escape using release_agent file. By running a container with certains capabilities, a privileged user can modify release_agent file and escape from the container.	container	mitre_privilege_escalation	T1611	process			True
maturity_stable	Directory traversal monitored file read	Web applications can be vulnerable to directory traversal attacks that allow accessing files outside of the web app's root directory (e.g. Arbitrary File Read bugs). System directories like /etc are typically accessed via absolute paths. Access patterns outside of this (here path traversal) can be regarded as suspicious. This rule includes failed file open attempts.	container, host	mitre_credential_access	T1555	filesystem			True
maturity_stable	Disallowed SSH Connection Non Standard Port	Detect any new outbound SSH connection from the host or container using a non-standard port. This rule holds the potential to detect a family of reverse shells that cause the victim machine to connect back out over SSH, with STDIN piped from the SSH connection to a shell's STDIN, and STDOUT of the shell piped back over SSH. Such an attack can be launched against any app that is vulnerable to command injection. The upstream rule only covers a limited selection of non-standard ports. We suggest adding more ports, potentially incorporating ranges based on your environment's knowledge and custom SSH port configurations. This rule can complement the "Redirect STDOUT/STDIN to Network Connection in Container" or "Disallowed SSH Connection" rule.	container, host	mitre_execution	T1059	network, process			True
maturity_stable	Drop and execute new binary in container	Detect if an executable not belonging to the base image of a container is being executed. The drop and execute pattern can be observed very often after an attacker gained an initial foothold. is_exe_upper_layer filter field only applies for container runtimes that use overlayfs as union mount filesystem. Adopters can utilize the provided template list known_drop_and_execute_containers containing allowed container images known to execute binaries not included in their base image. Alternatively, you could exclude non-production namespaces in Kubernetes settings by adjusting the rule further. This helps reduce noise by applying application and environment-specific knowledge to this rule. Common anti-patterns include administrators or SREs performing ad-hoc debugging.	container	mitre_persistence	TA0003	process	PCI_DSS_11.5.1		True
maturity_stable	Execution from /dev/shm	This rule detects file execution in the /dev/shm directory, a tactic often used by threat actors to store their readable, writable, and occasionally executable files. /dev/shm acts as a link to the host or other containers, creating vulnerabilities for their compromise as well. Notably, /dev/shm remains unchanged even after a container restart. Consider this rule alongside the newer "Drop and execute new binary in container" rule.	container, host	mitre_execution	T1059.004				True
maturity_stable	Fileless execution via memfd_create	Detect if a binary is executed from memory using the memfd_create technique. This is a well-known defense evasion technique for executing malware on a victim machine without storing the payload on disk and to avoid leaving traces about what has been executed. Adopters can whitelist processes that may use fileless execution for benign purposes by adding items to the list known_memfd_execution_processes.	container, host	mitre_defense_evasion	T1620	process			True
maturity_stable	Find AWS Credentials	Detect attempts to search for private keys or passwords using the grep or find command, particularly targeting standard AWS credential locations. This is often seen with unsophisticated attackers, as there are many ways to access files using bash built-ins that could go unnoticed. Regardless, this serves as a solid baseline detection that can be tailored to cover these gaps while maintaining an acceptable noise level. This rule complements the rule "Search Private Keys or Passwords".	container, host	mitre_credential_access	T1552	process, aws			True
maturity_stable	Linux Kernel Module Injection Detected	Inject Linux Kernel Modules from containers using insmod or modprobe with init_module and finit_module syscalls, given the precondition of sys_module effective capabilities. Profile the environment and consider allowed_container_images_loading_kernel_module to reduce noise and account for legitimate cases.	container, host	mitre_persistence	TA0003	process			True
maturity_stable	Netcat Remote Code Execution in Container	Netcat Program runs inside container that allows remote code execution and may be utilized as a part of a variety of reverse shell payload https://github.com/swisskyrepo/PayloadsAllTheThings/. These programs are of higher relevance as they are commonly installed on UNIX-like operating systems. Can fire in combination with the "Redirect STDOUT/STDIN to Network Connection in Container" rule as it utilizes a different evt.type.	container	mitre_execution	T1059	network, process			True
maturity_stable	PTRACE anti-debug attempt	Detect usage of the PTRACE system call with the PTRACE_TRACEME argument, indicating a program actively attempting to avoid debuggers attaching to the process. This behavior is typically indicative of malware activity. Read more about PTRACE in the "PTRACE attached to process" rule.	container, host	mitre_defense_evasion	T1622	process			True
maturity_stable	PTRACE attached to process	Detect an attempt to inject potentially malicious code into a process using PTRACE in order to evade process-based defenses or elevate privileges. Common anti-patterns are debuggers. Additionally, profiling your environment via the known_ptrace_procs template macro can reduce noise. A successful ptrace syscall generates multiple logs at once.	container, host	mitre_privilege_escalation	T1055.008	process			True
maturity_stable	Packet socket created in container	Detect new packet socket at the device driver (OSI Layer 2) level in a container. Packet socket could be used for ARP Spoofing and privilege escalation (CVE-2020-14386) by an attacker. Noise can be reduced by using the user_known_packet_socket_binaries template list.	container	mitre_credential_access	T1557.002	network			True
maturity_stable	Read sensitive file trusted after startup	An attempt to read any sensitive file (e.g. files containing user/password/authentication information) by a trusted program after startup. Trusted programs might read these files at startup to load initial state, but not afterwards. Can be customized as needed. In modern containerized cloud infrastructures, accessing traditional Linux sensitive files might be less relevant, yet it remains valuable for baseline detections. While we provide additional rules for SSH or cloud vendor-specific credentials, you can significantly enhance your security program by crafting custom rules for critical application credentials unique to your environment.	container, host	mitre_credential_access	T1555	filesystem			True
maturity_stable	Read sensitive file untrusted	An attempt to read any sensitive file (e.g. files containing user/password/authentication information). Exceptions are made for known trusted programs. Can be customized as needed. In modern containerized cloud infrastructures, accessing traditional Linux sensitive files might be less relevant, yet it remains valuable for baseline detections. While we provide additional rules for SSH or cloud vendor-specific credentials, you can significantly enhance your security program by crafting custom rules for critical application credentials unique to your environment.	container, host	mitre_credential_access	T1555	filesystem			True
maturity_stable	Redirect STDOUT/STDIN to Network Connection in Container	Detect redirection of stdout/stdin to a network connection within a container, achieved by utilizing a variant of the dup syscall (potential reverse shell or remote code execution https://github.com/swisskyrepo/PayloadsAllTheThings/). This detection is behavior-based and may generate noise in the system, and can be adjusted using the user_known_stand_streams_redirect_activities template macro. Tuning can be performed similarly to existing detections based on process lineage or container images, and/or it can be limited to interactive tty (tty != 0).	container	mitre_execution	T1059	network, process			True
maturity_stable	Remove Bulk Data from Disk	Detect a process running to clear bulk data from disk with the intention to destroy data, possibly interrupting availability to systems. Profile your environment and use user_known_remove_data_activities to tune this rule.	container, host	mitre_impact	T1485	process, filesystem			True
maturity_stable	Run shell untrusted	An attempt to spawn a shell below a non-shell application. The non-shell applications that are monitored are defined in the protected_shell_spawner macro, with protected_shell_spawning_binaries being the list you can easily customize. For Java parent processes, please note that Java often has a custom process name. Therefore, rely more on proc.exe to define Java applications. This rule can be noisier, as you can see in the exhaustive existing tuning. However, given it is very behavior-driven and broad, it is universally relevant to catch general Remote Code Execution (RCE). Allocate time to tune this rule for your use cases and reduce noise. Tuning suggestions include looking at the duration of the parent process (proc.ppid.duration) to define your long-running app processes. Checking for newer fields such as proc.vpgid.name and proc.vpgid.exe instead of the direct parent process being a non-shell application could make the rule more robust.	container, host	mitre_execution	T1059.004	process, shell			True
maturity_stable	Search Private Keys or Passwords	Detect attempts to search for private keys or passwords using the grep or find command. This is often seen with unsophisticated attackers, as there are many ways to access files using bash built-ins that could go unnoticed. Regardless, this serves as a solid baseline detection that can be tailored to cover these gaps while maintaining an acceptable noise level.	container, host	mitre_credential_access	T1552.001	process, filesystem			True
maturity_stable	System user interactive	System (e.g. non-login) users spawning new processes. Can add custom service users (e.g. apache or mysqld). 'Interactive' is defined as new processes as descendants of an ssh session or login process. Consider further tuning by only looking at processes in a terminal / tty (proc.tty != 0). A newer field proc.is_vpgid_leader could be of help to distinguish if the process was "directly" executed, for instance, in a tty, or executed as a descendant process in the same process group, which, for example, is the case when subprocesses are spawned from a script. Consider this rule as a great template rule to monitor interactive accesses to your systems more broadly. However, such a custom rule would be unique to your environment. The rule "Terminal shell in container" that fires when using "kubectl exec" is more Kubernetes relevant, whereas this one could be more interesting for the underlying host.	container, host	mitre_execution	T1059	users		NIST_800-53_AC-2	True
maturity_stable	Terminal shell in container	A shell was used as the entrypoint/exec point into a container with an attached terminal. Parent process may have legitimately already exited and be null (read container_entrypoint macro). Common when using "kubectl exec" in Kubernetes. Correlate with k8saudit exec logs if possible to find user or serviceaccount token used (fuzzy correlation by namespace and pod name). Rather than considering it a standalone rule, it may be best used as generic auditing rule while examining other triggered rules in this container/tty.	container	mitre_execution	T1059	shell			True

Incubating Falco Rules

31 incubating Falco rules (34.83% of rules):

maturity	rule	desc	workload	mitre_phase	mitre_ttp	extra_tags	compliance_pci_dss	compliance_nist	enabled
maturity_incubating	Adding ssh keys to authorized_keys	After gaining access, attackers can modify the authorized_keys file to maintain persistence on a victim host. Where authorized_keys files are modified via cloud APIs or command line interfaces, an adversary may achieve privilege escalation on the target virtual machine if they add a key to a higher-privileged user. This rules aims at detecting any modification to the authorized_keys file, that is usually located under the .ssh directory in any user's home directory. This rule complements the more generic auditing rule "Read ssh information" by specifically detecting the writing of new, potentially attacker-provided keys.	host	mitre_persistence	T1098.004	filesystem			True
maturity_incubating	BPF Program Not Profiled	BPF is a kernel technology that can be misused for malicious purposes, like "Linux Kernel Module Injection". This rule should be considered an auditing rule to notify you of any unprofiled BPF tools running in your environment. However, it requires customization after profiling your environment. BPF-powered agents make bpf syscalls all the time, so this rule only sends logs for BPF_PROG_LOAD calls (bpf cmd=5) in the enter event. If you also want to log whether the syscall failed or succeeded, remove the direction filter and add the evt.arg.res_or_fd output field.	container, host	mitre_persistence	TA0003				True
maturity_incubating	Backdoored library loaded into SSHD (CVE-2024-3094)	This rule detects possible CVE-2024-3094 exploitation when the SSH daemon process loads a vulnerable version of the liblzma library. An attacker could exploit this to interfere with authentication in sshd via systemd, potentially compromising sensitive data or escalating their privileges.	container, host	mitre_initial_access	T1556				True
maturity_incubating	Change namespace privileges via unshare	Unprivileged users in containers may not have CAP_SYS_ADMIN or other elevated privileges. However, they can use the unshare system call with CLONE_NEWNS or CLONE_NEWUSER to create or clone a namespace or user with the necessary privileges to conduct further attacks. It is best practice to block the unshare system call via seccomp if it is not needed. Misuse of unshare can be related to misconfigured Kubernetes clusters, for example.	container	mitre_privilege_escalation	T1611				True
maturity_incubating	Change thread namespace	An attempt to alter the namespace of a process (often performed while creating a container) through the setns syscall. Conversely, the same syscall setns is triggered when an unauthorized attempt is made to break out from the container to the host, for example, when using commands like nsenter --target 1 and similar ones. Recommending to profile your environment and refine this rule for effective operationalization.	container, host	mitre_privilege_escalation	T1611	process			True
maturity_incubating	Contact EC2 Instance Metadata Service From Container	Detects attempts to communicate with the EC2 Instance Metadata Service from a container. This detection is narrowly focused and might not apply to your environment. In addition, it could generate noise and require fine-tuning.	container	mitre_credential_access	T1552.005	network, aws			True
maturity_incubating	Contact cloud metadata service from container	Detects attempts to communicate with the Cloud Instance Metadata Service from a container. This detection is narrowly focused and might not apply to your environment. In addition, it could generate noise and require fine-tuning.	container	mitre_discovery	T1565	network			True
maturity_incubating	Create files below dev	Detect the creation of files under /dev except for authorized device management programs. This can reveal rootkits hiding files in /dev. Additionally, consider the "Execution from /dev/shm" rule. The upstream rule already covers some tuning scenarios that you can further expand upon.	host	mitre_persistence	T1543	filesystem			True
maturity_incubating	DB program spawned process	A program related to the database server creates an unexpected child process (other than itself). This is not supposed to happen and often follows SQL injection attacks. This behavioral detection could indicate potential unauthorized data extraction or tampering with the database.	container, host	mitre_execution	T1190	process, database			True
maturity_incubating	Delete or rename shell history	Detect shell history deletion, frequently used by unsophisticated adversaries to eliminate evidence. Note that it can also trigger when exiting a Terminal shell, such as with kubectl exec, which may introduce some noise.	container, host	mitre_defense_evasion	T1070	process, filesystem			True
maturity_incubating	Exfiltrating Artifacts via Kubernetes Control Plane	Detect the copying of artifacts from a container's file system using the Kubernetes control plane (kubectl cp). This rule can identify potential exfiltration of application secrets from containers' file systems, potentially revealing the outcomes of unauthorized access and control plane misuse via stolen identities (such as stolen credentials like Kubernetes serviceaccount tokens). Can be customized by the adopter to only monitor specific artifact paths, containers, or namespaces as needed.	container	mitre_exfiltration	TA0010	filesystem			True
maturity_incubating	Launch Excessively Capable Container	Identify containers that start with a powerful set of capabilities, with exceptions for recognized trusted images. Similar to the "Launch Privileged Container" rule, this functions as a robust auditing rule. Compromised highly privileged containers can lead to substantial harm. For instance, if another rule is triggered within such a container, it might raise suspicion, prompting closer scrutiny.	container	mitre_execution	T1610	cis			True
maturity_incubating	Launch Ingress Remote File Copy Tools in Container	Detect ingress remote file copy tools (such as curl or wget) launched inside containers. This rule can be considered a valuable auditing tool, but it has the potential to generate notable noise and requires careful profiling before full operationalization.	container	mitre_command_and_control	TA0011	network, process			True
maturity_incubating	Launch Package Management Process in Container	Detect package management processes executed within containers. An excellent auditing rule to monitor general drifts in containers. Particularly useful for newer rules like "Drop and execute new binary in container" during incident response investigations. This helps identify common anti-patterns of ad-hoc debugging. Simultaneously, to maintain optimal hygiene, it's recommended to prevent container drifts and instead opt for redeploying new containers.	container	mitre_persistence	T1505	process, software_mgmt			True
maturity_incubating	Launch Privileged Container	Detect the initial process initiation within a privileged container, with exemptions for known and trusted images. This rule primarily serves as an excellent auditing mechanism since highly privileged containers, when compromised, can result in significant harm. For instance, if another rule triggers within such a privileged container, it could be seen as more suspicious, prompting a closer inspection.	container	mitre_execution	T1610	cis	PCI_DSS_10.2.5		True
maturity_incubating	Launch Remote File Copy Tools in Container	Detect remote file copy tools (like rsync, scp, sftp, dcp) launched within a container, potentially indicating data exfiltration. Suggest refining this rule to accommodate legitimate use cases.	container	mitre_exfiltration	T1020	network, process			True
maturity_incubating	Launch Suspicious Network Tool in Container	Detect network tools (like netcat, nmap, tcpdump, socat, and more) launched within containers without any additional filters. This serves as a valuable general detection, but it's recommended to invest engineering effort to fine-tune it and prevent a high volume of legitimate logs. This rule complements the more specific "Netcat Remote Code Execution in Container" rule.	container	mitre_execution	T1059	network, process			True
maturity_incubating	Launch Suspicious Network Tool on Host	Detect network tools (like netcat, nmap, tcpdump, socat, and more) launched within containers without any additional filters. This serves as a valuable general detection, but it's recommended to invest engineering effort to fine-tune it and prevent a high volume of legitimate logs. The host equivalent of "Launch Suspicious Network Tool in Container.".	host	mitre_execution	T1059	network, process			True
maturity_incubating	Modify Shell Configuration File	Detect attempts to modify shell configuration files, primarily aimed at establishing persistence by automatically inserting commands into scripts executed by shells. The upstream rule excludes shell processes because they often create unnecessary noise. However, this might lead to missed detections. To customize the rule for your situation, you can fine-tune it using enhanced profiling. For example, you might want to only consider interactive shell processes (where proc.tty != 0).	container, host	mitre_persistence	T1546.004	filesystem			True
maturity_incubating	Mount Launched in Privileged Container	Detect filesystem mounts (using the mount binary) within a privileged container. Due to the elevated privileges, this action could be one of the TTPs used in an attempt to escape from a container to the host. This type of action is often preceded by reconnaissance activities, for which you can also create custom rules.	container	mitre_privilege_escalation	T1611	cis, filesystem			True
maturity_incubating	Network Connection outside Local Subnet	Detect network traffic (inbound or outbound) from a container to a destination outside the local subnet. To operationalize this rule, profile your environment and update the template macro namespace_scope_network_only_subnet. Customizing network-related rules usually demands substantial engineering effort to ensure their functionality.	container	mitre_discovery	T1046	network	PCI_DSS_6.4.2		True
maturity_incubating	Non sudo setuid	Detect attempts to change users through the use of setuid, with exceptions for sudo/su. The users "root" and "nobody" using setuid on themselves are also excluded, as setuid calls in these cases typically involve reducing privileges. By setting the setuid bit, an attacker could execute code in a different user's context, potentially with higher privileges. One drawback is the potential for noise, as many applications legitimately use this approach.	container, host	mitre_privilege_escalation	T1548.001	users			True
maturity_incubating	Potential Local Privilege Escalation via Environment Variables Misuse	Process run with suspect environment variable that could be attempting privilege escalation. One use case is detecting the use of the GLIBC_TUNABLES environment variable, which could be used for privilege escalation on systems running vulnerable glibc versions. Only known and carefully profiled processes that legitimately exhibit this behavior should be excluded from this rule. This rule is expected to trigger on every attempt, even failed ones.	container, host	mitre_privilege_escalation	TA0004	users			True
maturity_incubating	Program run with disallowed http proxy env	Detect curl or wget usage with HTTP_PROXY environment variable. Attackers can manipulate the HTTP_PROXY variable's value to redirect application's internal HTTP requests. This could expose sensitive information like authentication keys and private data.	container, host	mitre_execution	T1204	users			True
maturity_incubating	Read environment variable from /proc files	An attempt to read process environment variables from /proc files. The consequences are akin to accessing traditional sensitive files, as sensitive data, including secrets, might be stored in environment variables. Understanding your environment, such as identifying critical namespaces, and incorporating extra filtering statements to alert exclusively for those, can enhance the rule's effectiveness.	container	mitre_discovery	T1083	filesystem, process			True
maturity_incubating	Read ssh information	This rule identifies attempts to read files within ssh directories using programs that are not related to ssh. It's a simple and versatile detection method that works well alongside more specific rules focused on sensitive file access. You have a couple of options for using this rule effectively: you can adjust the specialized rules to cover all the important scenarios and ensure precedence in rule smatching for those, or you can analyze the combined view of ssh-related file access across various rules on your downstream computing platform. Just like with other rules, you can narrow down monitoring to specific processes, or you can limit it to interactive access only.	container, host	mitre_collection	T1005	filesystem			True
maturity_incubating	Schedule Cron Jobs	Detect scheduled cron jobs; this is a highly generic detection and certainly needs adjustments and profiling in your environment before operationalization. Simultaneously, exploiting the functionality of cron jobs is among one of the oldest TTPs used by adversaries.	container, host	mitre_execution	T1053.003	filesystem			True
maturity_incubating	Set Setuid or Setgid bit	This rule is focused on detecting the use of setuid or setgid bits set via chmod. These bits, when set for an application, result in the application running with the privileges of the owning user or group. By enabling the setuid or setgid bits, an attacker could run code in a different user's context, possibly with elevated privileges. However, there's a trade-off with noise, given that numerous applications legitimately run chmod. This rule is related to the "Non sudo setuid" rule.	container, host	mitre_privilege_escalation	T1548.001	process, users			True
maturity_incubating	System procs network activity	Detect any unexpected network activity performed by system binaries that typically shouldn't perform network activity, including coreutils binaries (like sleep, mkdir, who, date, and others) or user management binaries (such as login, systemd, usermod, deluser, adduser, chpasswd, and others). This serves as a valuable baseline detection for network-related activities.	host	mitre_execution	T1059	network, process			True
maturity_incubating	Unexpected UDP Traffic	Detecting UDP traffic on ports other than 53 (DNS) or other commonly used ports. Misusing UDP is a known TTP among attackers. Monitoring unusual network activity is highly valuable but often generates significant noise, as is the case with this detection.	container, host	mitre_exfiltration	TA0011	network			True
maturity_incubating	User mgmt binaries	Detect activity by any programs that can manage users, passwords, or permissions (such as login, systemd, usermod, deluser, adduser, chpasswd, and others). sudo and su are excluded. Activity in containers is also excluded -- some containers create custom users on top of a base linux distribution at startup. Some innocuous command lines that don't actually change anything are excluded. You might want to consider applying this rule to container actions as well.	host	mitre_persistence	T1098	users, software_mgmt			True

Sandbox Falco Rules

29 sandbox Falco rules (32.58% of rules):

maturity	rule	desc	workload	mitre_phase	mitre_ttp	extra_tags	compliance_pci_dss	compliance_nist	enabled
maturity_sandbox	Basic Interactive Reconnaissance	This rule detects basic interactive reconnaissance commands that are typically run by unsophisticated attackers or used in internal Red Team exercises. Interactive is defined as a terminal being present (proc.tty != 0). This could be any form of reverse shell or usage of kubectl exec or ssh etc. In addition, filtering for the process being the process group leader indicates that the command was "directly" typed into the terminal and not run as a result of a script. This rule is a basic auditing or template rule. You can expand the list of reconnaissance commands, such as by adding "ls". Common anti-patterns are SRE activity or debugging, but it is still worth capturing this generically. Typically, you would expect other rules to fire as well in relation to this activity.	container, host	mitre_reconnaissance	TA0043	process			True
maturity_sandbox	Container Drift Detected (chmod)	Detect new executables created within a container as a result of chmod. While this detection can generate significant noise, chmod usage is frequently linked to dropping and executing malicious implants. The newer rule "Drop and execute new binary in container" provides more precise detection of this TTP using unambiguous kernel signals. It is recommended to use the new rule. However, this rule might be more relevant for auditing if applicable in your environment, such as when chmod is used on files within the /tmp folder.	container	mitre_execution	T1059	process, filesystem			False
maturity_sandbox	Container Drift Detected (open+create)	Detect new executables created within a container as a result of open+create. The newer rule "Drop and execute new binary in container" provides more precise detection of this TTP using unambiguous kernel signals. It is recommended to use the new rule.	container	mitre_execution	T1059	process, filesystem			False
maturity_sandbox	Container Run as Root User	Container detected running as the root user. This should be taken into account especially when policies disallow containers from running with root user privileges. Note that a root user in containers doesn't inherently possess extensive power, as modern container environments define privileges through Linux capabilities. To learn more, check out the rule "Launch Privileged Container".	container	mitre_execution	T1610	process, users			False
maturity_sandbox	Create Hidden Files or Directories	Detecting hidden files or directories creation can serve as an auditing rule to track general system changes. Such rules can be noisy and challenging to interpret, particularly if your system frequently undergoes updates. However, careful profiling of your environment can transform this rule into an effective rule for detecting unusual behavior associated with system changes, including compliance-related cases.	container, host	mitre_defense_evasion	T1564.001	filesystem			False
maturity_sandbox	Decoding Payload in Container	Detect any use of {base64} decoding in a container. Legitimate applications may decode encoded payloads. The template list known_decode_payload_containers can be used for simple tuning and customization, or you can adopt custom, more refined tuning. Less sophisticated adversaries may {base64}-decode their payloads not only to obfuscate them, but also to ensure that the payload remains intact when the application processes it. Note that injecting commands into an application's input often results in the application processing passed strings like "sh -c". In these cases, you may be lucky and the encoded blob will also be logged. Otherwise, all you will see is the {base64} decoding command, as the encoded blob was already interpreted by the shell.	container	mitre_command_and_control	T1132	process			True
maturity_sandbox	Detect crypto miners using the Stratum protocol	Miners commonly specify the mining pool to connect to using a URI that starts with "stratum+tcp". However, this rule is highly specific to this technique, and matching command-line arguments can generally be bypassed quite easily.	container, host	mitre_impact	T1496	process			True
maturity_sandbox	Detect outbound connections to common miner pool ports	Miners usually connect to miner pools using standard ports, and this rule flags such activity. Important: Falco currently sends DNS requests to resolve miner pool domains, which could trigger other alerts. Prior to enabling this rule, it's advised to ensure whether this is acceptable for your environment. This rule is specifically disabled for that reason.	container, host	mitre_impact	T1496	network			False
maturity_sandbox	Interpreted procs inbound network activity	Any inbound network activity performed by any interpreted program (perl, python, ruby, etc.). While it offers broad coverage and behavioral insights, operationalizing it effectively requires significant time and might result in a moderate level of noise. Suggesting customizing this rule to be more specific. For example, you could set it up to alert only for important namespaces after studying their usual behavior.	container, host	mitre_exfiltration	TA0011	network			False
maturity_sandbox	Interpreted procs outbound network activity	Any outbound network activity performed by any interpreted program (perl, python, ruby, etc.). While it offers broad coverage and behavioral insights, operationalizing it effectively requires significant time and might result in a moderate level of noise. Suggesting customizing this rule to be more specific. For example, you could set it up to alert only for important namespaces after studying their usual behavior.	container, host	mitre_exfiltration	TA0011	network			False
maturity_sandbox	Java Process Class File Download	Detecting a Java process downloading a class file which could indicate a successful exploit of the log4shell Log4j vulnerability (CVE-2021-44228). This rule is highly specific in its scope.	container, host	mitre_initial_access	T1190	process			False
maturity_sandbox	Kubernetes Client Tool Launched in Container	Detect the execution of a Kubernetes client tool (like docker, kubectl, crictl) within a container, which is typically not expected behavior. Although this rule targets container workloads, monitoring the use of tools like crictl on the host over interactive access could also be valuable for broader auditing objectives.	container	mitre_execution	T1610				True
maturity_sandbox	Launch Disallowed Container	Detect the initial process launched within a container that is not in a list of allowed containers. This rule holds value for generic auditing; however, this rule requires a good understanding of your setup and consistent effort to keep the list of allowed containers current. In some situations, this can be challenging to manage.	container	mitre_lateral_movement	T1610				True
maturity_sandbox	Launch Sensitive Mount Container	Detect the initial process launched within a container that has a mount from a sensitive host directory (e.g. /proc). Exceptions are made for known trusted images. This rule holds value for generic auditing; however, its noisiness varies based on your environment.	container	mitre_execution	T1610	cis			True
maturity_sandbox	Mkdir binary dirs	Trying to create a directory below a set of binary directories can serve as an auditing rule to track general system changes. Such rules can be noisy and challenging to interpret, particularly if your system frequently undergoes updates. However, careful profiling of your environment can transform this rule into an effective rule for detecting unusual behavior associated with system changes, including compliance-related cases.	container, host	mitre_persistence	T1222.002	filesystem			True
maturity_sandbox	Modify Container Entrypoint	This rule detect an attempt to write on container entrypoint symlink (/proc/self/exe). Possible CVE-2019-5736 Container Breakout exploitation attempt. This rule has a more narrow scope.	container	mitre_initial_access	T1611	filesystem			False
maturity_sandbox	Modify binary dirs	Trying to modify any file below a set of binary directories can serve as an auditing rule to track general system changes. Such rules can be noisy and challenging to interpret, particularly if your system frequently undergoes updates. However, careful profiling of your environment can transform this rule into an effective rule for detecting unusual behavior associated with system changes, including compliance-related cases.	container, host	mitre_defense_evasion	T1222.002	filesystem			True
maturity_sandbox	Polkit Local Privilege Escalation Vulnerability (CVE-2021-4034)	This rule detects attempts to exploit a privilege escalation vulnerability in Polkit's pkexec. Through the execution of specially crafted code, a local user can exploit this weakness to attain root privileges on a compromised system. This rule is highly specific in its scope.	container, host	mitre_privilege_escalation	TA0004	process, users			True
maturity_sandbox	Read Shell Configuration File	This rule detects attempts made by non-shell programs to read shell configuration files. It offers additional generic auditing. It serves as a baseline detection alert for unusual shell configuration file accesses. The rule "Modify Shell Configuration File" might be more relevant and adequate for your specific cases.	container, host	mitre_discovery	T1546.004	filesystem			False
maturity_sandbox	Sudo Potential Privilege Escalation	Affecting sudo (<= 1.9.5p2), there's a privilege escalation vulnerability. By executing sudo using the sudoedit -s or sudoedit -i command with a command-line argument that ends with a single backslash character, an unprivileged user can potentially escalate privileges to root. This rule is highly specific and might be bypassed due to potential issues with string matching on command line arguments.	container, host	mitre_privilege_escalation	T1548.003	filesystem, users			True
maturity_sandbox	Unexpected K8s NodePort Connection	Detect attempts to utilize K8s NodePorts from a container. K8s NodePorts are accessible on the eth0 interface of each node, and they facilitate external traffic into a Kubernetes cluster. Attackers could misuse them for unauthorized access. The rule uses default port ranges, but check for custom ranges and make necessary adjustments. Also, consider tuning this rule as needed.	container	mitre_persistence	T1205.001	network, k8s		NIST_800-53_AC-6	False
maturity_sandbox	Unexpected inbound connection source	Detect any inbound connection from a source outside of an allowed set of ips, networks, or domain names. This rule absolutely requires profiling your environment beforehand. Network-based rules are extremely crucial in any security program, as they can often provide the only definitive evidence. However, effectively operationalizing them can be challenging due to the potential for noise.	container, host	mitre_command_and_control	TA0011	network			False
maturity_sandbox	Unprivileged Delegation of Page Faults Handling to a Userspace Process	Detect a successful unprivileged userfaultfd syscall, which could serve as an attack primitive for exploiting other vulnerabilities. To fine-tune this rule, consider using the template list "user_known_userfaultfd_processes".	container, host	mitre_defense_evasion	TA0005	process			True
maturity_sandbox	Update Package Repository	This rule generically detects updates to package repositories and can be seen as an auditing measure. Recommend evaluating its relevance for your specific environment.	container, host	mitre_execution	T1072	filesystem			True
maturity_sandbox	Write below binary dir	Trying to write to any file below specific binary directories can serve as an auditing rule to track general system changes. Such rules can be noisy and challenging to interpret, particularly if your system frequently undergoes updates. However, careful profiling of your environment can transform this rule into an effective rule for detecting unusual behavior associated with system changes, including compliance-related cases.	container, host	mitre_persistence	T1543	filesystem			True
maturity_sandbox	Write below etc	Trying to write to any file below /etc can serve as an auditing rule to track general system changes. Such rules can be noisy and challenging to interpret, particularly if your system frequently undergoes updates. However, careful profiling of your environment can transform this rule into an effective rule for detecting unusual behavior associated with system changes, including compliance-related cases.	container, host	mitre_persistence	T1098	filesystem			True
maturity_sandbox	Write below monitored dir	Trying to write to any file below a set of monitored directories can serve as an auditing rule to track general system changes. Such rules can be noisy and challenging to interpret, particularly if your system frequently undergoes updates. However, careful profiling of your environment can transform this rule into an effective rule for detecting unusual behavior associated with system changes, including compliance-related cases.	container, host	mitre_persistence	T1543	filesystem			True
maturity_sandbox	Write below root	Trying to write to any file directly below / or /root can serve as an auditing rule to track general system changes. Such rules can be noisy and challenging to interpret, particularly if your system frequently undergoes updates. However, careful profiling of your environment can transform this rule into an effective rule for detecting unusual behavior associated with system changes, including compliance-related cases. Lastly, this rule stands out as potentially the noisiest one among rules related to "write below.	container, host	mitre_persistence	TA0003	filesystem			True
maturity_sandbox	Write below rpm database	Trying to write to the rpm database by any non-rpm related program can serve as an auditing rule to track general system changes. Such rules can be noisy and challenging to interpret, particularly if your system frequently undergoes updates. However, careful profiling of your environment can transform this rule into an effective rule for detecting unusual behavior associated with system changes, including compliance-related cases.	container, host	mitre_persistence	T1072	filesystem, software_mgmt			True

Deprecated Falco Rules

4 deprecated Falco rules (4.49% of rules):

maturity	rule	desc	workload	mitre_phase	mitre_ttp	extra_tags	compliance_pci_dss	compliance_nist	enabled
maturity_deprecated	Disallowed SSH Connection	Detect any new SSH connection on port 22 to a host other than those in an allowed list of hosts. This rule absolutely requires profiling your environment beforehand. Network-based rules are extremely crucial in any security program, as they can often provide the only definitive evidence. However, effectively operationalizing them can be challenging due to the potential for noise.	container, host	mitre_lateral_movement	T1021.004	network			False
maturity_deprecated	Outbound Connection to C2 Servers	Detect outbound connections to command and control servers using a list of IP addresses and fully qualified domain names (FQDNs). This rule absolutely requires profiling your environment beforehand and also necessitates adjusting the template lists. The current expression logic will never evaluate to true unless the lists are populated. Network-based rules are extremely crucial in any security program, as they can often provide the only definitive evidence. However, effectively operationalizing them can be challenging due to the potential for noise. Notably, this rule is challenging to operationalize.	container, host	mitre_command_and_control	TA0011	network			False
maturity_deprecated	Outbound or Inbound Traffic not to Authorized Server Process and Port	Detect traffic to an unauthorized server process and port within pre-defined containers. This rule absolutely requires profiling your environment beforehand and also necessitates adjusting the list of containers to which this rule will be applied. The current expression logic will never evaluate to true unless the list is populated. Network-based rules are extremely crucial in any security program, as they can often provide the only definitive evidence. However, effectively operationalizing them can be challenging due to the potential for noise. Notably, this rule is challenging to operationalize.	container	mitre_discovery	TA0011	network		NIST_800-53_CM-7	False
maturity_deprecated	Unexpected outbound connection destination	Detect any outbound connection to a destination outside of an allowed set of ips, networks, or domain names. This rule absolutely requires profiling your environment beforehand. Network-based rules are extremely crucial in any security program, as they can often provide the only definitive evidence. However, effectively operationalizing them can be challenging due to the potential for noise.	container, host	mitre_command_and_control	TA0011	network			False

Falco Rules Stats

Falco rules per workload type:

workload	rule_count	percentage
container	31	34.83%
container, host	53	59.55%
host	5	5.62%

Falco rules per Mitre Attack phase:

mitre_phase	rules	percentage
mitre_collection	maturity_incubating: Read ssh information	1.12%
mitre_command_and_control	maturity_sandbox: Decoding Payload in Container	5.62%
	maturity_incubating: Launch Ingress Remote File Copy Tools in Container
	maturity_deprecated: Outbound Connection to C2 Servers
	maturity_sandbox: Unexpected inbound connection source
	maturity_deprecated: Unexpected outbound connection destination
mitre_credential_access	maturity_incubating: Contact EC2 Instance Metadata Service From Container	10.11%
	maturity_stable: Create Hardlink Over Sensitive Files
	maturity_stable: Create Symlink Over Sensitive Files
	maturity_stable: Directory traversal monitored file read
	maturity_stable: Find AWS Credentials
	maturity_stable: Packet socket created in container
	maturity_stable: Read sensitive file trusted after startup
	maturity_stable: Read sensitive file untrusted
	maturity_stable: Search Private Keys or Passwords
mitre_defense_evasion	maturity_stable: Clear Log Activities	7.87%
	maturity_sandbox: Create Hidden Files or Directories
	maturity_incubating: Delete or rename shell history
	maturity_stable: Fileless execution via memfd_create
	maturity_sandbox: Modify binary dirs
	maturity_stable: PTRACE anti-debug attempt
	maturity_sandbox: Unprivileged Delegation of Page Faults Handling to a Userspace Process
mitre_discovery	maturity_stable: Contact K8S API Server From Container	6.74%
	maturity_incubating: Contact cloud metadata service from container
	maturity_incubating: Network Connection outside Local Subnet
	maturity_deprecated: Outbound or Inbound Traffic not to Authorized Server Process and Port
	maturity_sandbox: Read Shell Configuration File
	maturity_incubating: Read environment variable from /proc files
mitre_execution	maturity_sandbox: Container Drift Detected (chmod)	23.6%
	maturity_sandbox: Container Drift Detected (open+create)
	maturity_sandbox: Container Run as Root User
	maturity_incubating: DB program spawned process
	maturity_stable: Disallowed SSH Connection Non Standard Port
	maturity_stable: Execution from /dev/shm
	maturity_sandbox: Kubernetes Client Tool Launched in Container
	maturity_incubating: Launch Excessively Capable Container
	maturity_incubating: Launch Privileged Container
	maturity_sandbox: Launch Sensitive Mount Container
	maturity_incubating: Launch Suspicious Network Tool in Container
	maturity_incubating: Launch Suspicious Network Tool on Host
	maturity_stable: Netcat Remote Code Execution in Container
	maturity_incubating: Program run with disallowed http proxy env
	maturity_stable: Redirect STDOUT/STDIN to Network Connection in Container
	maturity_stable: Run shell untrusted
	maturity_incubating: Schedule Cron Jobs
	maturity_incubating: System procs network activity
	maturity_stable: System user interactive
	maturity_stable: Terminal shell in container
	maturity_sandbox: Update Package Repository
mitre_exfiltration	maturity_incubating: Exfiltrating Artifacts via Kubernetes Control Plane	5.62%
	maturity_sandbox: Interpreted procs inbound network activity
	maturity_sandbox: Interpreted procs outbound network activity
	maturity_incubating: Launch Remote File Copy Tools in Container
	maturity_incubating: Unexpected UDP Traffic
mitre_impact	maturity_sandbox: Detect crypto miners using the Stratum protocol	3.37%
	maturity_sandbox: Detect outbound connections to common miner pool ports
	maturity_stable: Remove Bulk Data from Disk
mitre_initial_access	maturity_incubating: Backdoored library loaded into SSHD (CVE-2024-3094)	3.37%
	maturity_sandbox: Java Process Class File Download
	maturity_sandbox: Modify Container Entrypoint
mitre_lateral_movement	maturity_deprecated: Disallowed SSH Connection	2.25%
	maturity_sandbox: Launch Disallowed Container
mitre_persistence	maturity_incubating: Adding ssh keys to authorized_keys	16.85%
	maturity_incubating: BPF Program Not Profiled
	maturity_incubating: Create files below dev
	maturity_stable: Drop and execute new binary in container
	maturity_incubating: Launch Package Management Process in Container
	maturity_stable: Linux Kernel Module Injection Detected
	maturity_sandbox: Mkdir binary dirs
	maturity_incubating: Modify Shell Configuration File
	maturity_sandbox: Unexpected K8s NodePort Connection
	maturity_incubating: User mgmt binaries
	maturity_sandbox: Write below binary dir
	maturity_sandbox: Write below etc
	maturity_sandbox: Write below monitored dir
	maturity_sandbox: Write below root
	maturity_sandbox: Write below rpm database
mitre_privilege_escalation	maturity_incubating: Change namespace privileges via unshare	12.36%
	maturity_incubating: Change thread namespace
	maturity_stable: Debugfs Launched in Privileged Container
	maturity_stable: Detect release_agent File Container Escapes
	maturity_incubating: Mount Launched in Privileged Container
	maturity_incubating: Non sudo setuid
	maturity_stable: PTRACE attached to process
	maturity_sandbox: Polkit Local Privilege Escalation Vulnerability (CVE-2021-4034)
	maturity_incubating: Potential Local Privilege Escalation via Environment Variables Misuse
	maturity_incubating: Set Setuid or Setgid bit
	maturity_sandbox: Sudo Potential Privilege Escalation
mitre_reconnaissance	maturity_sandbox: Basic Interactive Reconnaissance	1.12%

Compliance-related Falco rules:

compliance_tag	rules
NIST_800-53_AC-2	System user interactive
NIST_800-53_AC-6	Unexpected K8s NodePort Connection
NIST_800-53_AU-10	Clear Log Activities
NIST_800-53_CM-7	Outbound or Inbound Traffic not to Authorized Server Process and Port
PCI_DSS_10.2.5	Launch Privileged Container
PCI_DSS_11.5.1	Drop and execute new binary in container
PCI_DSS_6.4.2	Network Connection outside Local Subnet