Detect Proc Filesystem in Sumo Logic CSE
Adversaries on Linux systems read process memory directly via the /proc filesystem to extract credentials from running processes. By accessing /proc/<PID>/maps to identify memory regions and /proc/<PID>/mem to read those regions, attackers dump credentials from processes like sshd, su, sudo, gnome-keyring, and KWallet without injecting code or using ptrace. Tools include MimiPenguin (specifically targeting sshd and gnome-keyring), LaZagne (Linux edition), and PACEMAKER. This technique requires root privileges or the same UID as the target process. Used by threat actors targeting Linux servers where traditional Windows credential tools don't apply.
MITRE ATT&CK
- Tactic
- Credential Access
- Technique
- T1003 OS Credential Dumping
- Sub-technique
- T1003.007 Proc Filesystem
- Canonical reference
- https://attack.mitre.org/techniques/T1003/007/
Sumo Detection Query
(_sourceCategory="linux/audit" OR _sourceCategory="linux/syslog" OR _sourceCategory="os/linux")
| where _raw matches /\/proc\/\d+\/(mem|maps|environ)/ OR _raw matches /mimipenguin|lazagne|pacemaker/i
| parse regex field=_raw "exe=\"(?<exe>[^\"]+)\""
| parse regex field=_raw "name=\"(?<accessed_file>[^\"]+)\""
| parse regex field=_raw "syscall=(?<syscall>\S+)"
| parse regex field=_raw "pid=(?<pid>\d+)"
| parse regex field=_raw "uid=(?<uid>\d+)"
| parse regex field=_raw "hostname=(?<hostname>\S+)"
| parse regex field=accessed_file "/proc/(?<target_pid>\d+)/(?<proc_entry>\S+)" nodrop
| where !(exe matches /\/(gdb|strace|ltrace|cat)$/)
| eval risk = if(exe matches /python|perl|ruby|bash/ && accessed_file matches /\/proc\/\d+\/mem/, "HighRisk",
if(exe matches /mimipenguin|lazagne|pacemaker/i, "KnownTool",
if(accessed_file matches /\/proc\/\d+\/(mem|maps|environ)/, "Review", "Unknown")))
| where risk in ("HighRisk", "KnownTool", "Review")
| fields _messageTime, hostname, exe, uid, pid, target_pid, proc_entry, accessed_file, syscall, risk
| sort by _messageTime desc
// Union: Known tool names in syslog/secure logs
// Run separately and correlate:
// (_sourceCategory="linux/secure" OR _sourceCategory="linux/syslog")
// | where _raw matches /mimipenguin|MimiPenguin|lazagne|PACEMAKER/i
// | parse regex "(?<process>\\S+)\\[(?<pid>\\d+)\\]" nodrop
// | fields _messageTime, _sourceHost, process, pid, _rawSumo Logic detection for T1003.007 Proc Filesystem credential dumping on Linux. Parses auditd and syslog events to identify suspicious access to /proc/<PID>/mem, /proc/<PID>/maps, and /proc/<PID>/environ by non-debugger processes. Assigns risk tiers (HighRisk/KnownTool/Review) and extracts key forensic fields including target process PID, syscall type, and executing binary path.
Data Sources
Required Tables
False Positives & Tuning
- Security scanning tools such as ClamAV or AIDE that read process memory maps as part of behavioral monitoring or rootkit detection
- Language runtimes (Python, Ruby, Perl) executing legitimate administrative tasks that incidentally access /proc entries for self-inspection or inter-process communication
- CI/CD pipeline agents or test harnesses that invoke debugging-adjacent tools during integration testing on Linux build nodes
Other platforms for T1003.007
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1MimiPenguin Linux Credential Dump
Expected signal: Auditd SYSCALL events for openat on /proc/<PID>/mem with exe=/usr/bin/python3. DeviceFileEvents (if MDE Linux agent present) for /proc/*/mem access by python3. Syslog entries if gnome-keyring or sshd crash due to memory access attempt.
- Test 2Manual /proc/mem Credential Extraction
Expected signal: Auditd SYSCALL openat events for /proc/<PID>/maps with exe=/bin/cat or /bin/bash. Process creation event for pgrep sshd. DeviceProcessEvents for pgrep and cat with /proc path arguments.
- Test 3LaZagne Linux Memory Module
Expected signal: DeviceProcessEvents for lazagne binary execution with 'memory' argument. Auditd execve event for /tmp/lazagne. Auditd openat events for /proc/*/mem if memory module runs. Network connection to GitHub for download (DeviceNetworkEvents).
References (6)
- https://attack.mitre.org/techniques/T1003/007/
- https://github.com/huntergregal/mimipenguin
- https://github.com/AlessandroZ/LaZagne
- https://security.stackexchange.com/questions/91040/what-is-proc-pid-mem
- https://www.slideshare.net/roottoor1/linux-credential-access-techniques
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1003.007/T1003.007.md
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