Adversaries may gather credentials from the proc filesystem or /proc. The proc filesystem is a pseudo-filesystem used as an interface to kernel data structures for Linux based systems managing virtual memory. For each process, the /proc/<PID>/maps file shows how memory is mapped within the process’s virtual address space. And /proc/<PID>/mem, exposed for debugging purposes, provides access to the process’s virtual address space.(Citation: Picus Labs Proc cump 2022)(Citation: baeldung Linux proc map 2022)
When executing with root privileges, adversaries can search these memory locations for all processes on a system that contain patterns indicative of credentials. Adversaries may use regex patterns, such as <code>grep -E "^[0-9a-f-]* r" /proc/"$pid"/maps | cut -d' ' -f 1</code>, to look for fixed strings in memory structures or cached hashes.(Citation: atomic-red proc file system) When running without privileged access, processes can still view their own virtual memory locations. Some services or programs may save credentials in clear text inside the process’s memory.(Citation: MimiPenguin GitHub May 2017)(Citation: Polop Linux PrivEsc Gitbook)
If running as or with the permissions of a web browser, a process can search the /maps & /mem locations for common website credential patterns (that can also be used to find adjacent memory within the same structure) in which hashes or cleartext credentials may be located.
| Capability ID | Capability Description | Mapping Type | ATT&CK ID | ATT&CK Name | Notes |
|---|---|---|---|---|---|
| PR.AA-05.02 | Privileged system access | Mitigates | T1003.007 | Proc Filesystem |
Comments
This diagnostic statement protects against Proc Filesystem through the use of privileged account management and the use of multi-factor authentication.
References
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| DE.CM-06.02 | Third-party access monitoring | Mitigates | T1003.007 | Proc Filesystem |
Comments
This diagnostic statement protects against Proc Filesystem through the use of privileged account management. Employing auditing, privilege access management, and just in time access protects against adversaries trying to obtain illicit access to critical systems.
References
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| PR.AA-01.01 | Identity and credential management | Mitigates | T1003.007 | Proc Filesystem |
Comments
This diagnostic statement protects against Proc Filesystem through the use of hardened access control policies, secure defaults, password complexity requirements, multifactor authentication requirements, and removal of terminated accounts.
References
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| Capability ID | Capability Description | Mapping Type | ATT&CK ID | ATT&CK Name | Notes |
|---|---|---|---|---|---|
| amazon_inspector | Amazon Inspector | technique_scores | T1003.007 | Proc Filesystem |
Comments
The Amazon Inspector Best Practices assessment package can assess security control "Configure permissions for system directories" that prevents privilege escalation by local users and ensures only the root account can modify/execute system configuration information and binaries. Amazon Inspector does not directly protect against system modifications rather it just checks to see if security controls are in place which can inform decisions around hardening the system. Due to this and the fact the security control is only supported for Linux platforms, the score is Minimal.
References
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