Detect File and Directory Discovery in Sumo Logic CSE
Adversaries may enumerate files and directories or search specific filesystem locations to gather information about a host or network share. This discovery technique helps adversaries identify sensitive files, understand the environment, and shape follow-on behavior such as targeted exfiltration or lateral movement. Common tools include dir, tree, ls, find, locate, and forfiles. Adversaries may also search for credential files, configuration files, or documents with specific extensions using recursive enumeration patterns.
MITRE ATT&CK
- Tactic
- Discovery
- Technique
- T1083 File and Directory Discovery
- Canonical reference
- https://attack.mitre.org/techniques/T1083/
Sumo Detection Query
_sourceCategory=windows/sysmon OR _sourceCategory=windows/security
| where EventID in ("1", "4688")
| parse field=CommandLine "*" as cmdline nodrop
| parse field=ParentImage "*" as parent_image nodrop
| parse field=Image "*" as proc_image nodrop
// Normalize fields
| eval cmdline = toLowerCase(cmdline)
| eval parent_image = toLowerCase(parent_image)
| eval proc_image = toLowerCase(proc_image)
// Filter to file discovery processes
| where proc_image matches /(?:cmd\.exe|powershell\.exe|pwsh\.exe|find\.exe|where\.exe)/
| where cmdline matches /(?:dir\s|tree\s|forfiles|get-childitem|\bgci\b|get-item|find\s)/
// Score recursive flags
| eval IsRecursive = if(cmdline matches /(?:\/s|\/S|-recurse|-r\s|--recursive|-R\s)/, 1, 0)
// Score credential hunting
| eval HuntsCredentials = if(cmdline matches /(?:\.key|\.pem|\.pfx|\.p12|\.kdbx|id_rsa|authorized_keys|\.ppk|password|passwd|credential|secret|\.aws|web\.config|appsettings)/, 2, 0)
// Score suspicious parent processes
| eval IsSuspiciousParent = if(parent_image matches /(?:winword|excel|powerpnt|outlook|mshta|wscript|cscript|regsvr32|rundll32|msiexec|msedge|chrome|firefox)/, 2, 0)
// Score sensitive path targeting
| eval TargetsSensitivePath = if(cmdline matches /(?:\\users\\|\\appdata\\|\\documents\\|\\desktop\\|\\temp\\|\\ssh\\|\.aws|\.config|inetpub|wwwroot)/, 1, 0)
// Compute total score
| eval SuspicionScore = IsRecursive + HuntsCredentials + IsSuspiciousParent + TargetsSensitivePath
| where SuspicionScore >= 2
| fields _messageTime, Computer, User, proc_image, cmdline, parent_image, IsRecursive, HuntsCredentials, IsSuspiciousParent, TargetsSensitivePath, SuspicionScore
| sort by SuspicionScore desc, _messageTime descSumo Logic query detecting T1083 file and directory discovery using Sysmon Event ID 1 or Windows Security Event ID 4688. Applies a weighted suspicion scoring model across recursive enumeration patterns, credential file hunting, sensitive path targeting, and suspicious parent process spawning. Alerts when combined score reaches threshold of 2 or more.
Data Sources
Required Tables
False Positives & Tuning
- Automated patch management platforms (e.g., ManageEngine, Ivanti) running PowerShell Get-ChildItem to audit installed software or config state
- Security scanning tools like Tenable Nessus or Qualys agents that enumerate directories as part of credentialed scans
- User-initiated file searches via Windows Explorer or third-party tools (Everything, Agent Ransack) that internally invoke dir or find
Other platforms for T1083
Testing Methodology
Validate this detection against 5 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 1Recursive Directory Listing via CMD
Expected signal: Sysmon Event ID 1: Process Create with Image=cmd.exe, CommandLine containing 'dir /s /b C:\Users'. Security Event ID 4688 (if command line auditing enabled). Sysmon Event ID 11: File Create for %TEMP%\df00tech-dir-test.txt. Parent process will be the shell or test runner invoking the command.
- Test 2Credential File Search via PowerShell
Expected signal: Sysmon Event ID 1: Process Create with Image=powershell.exe, CommandLine containing 'Get-ChildItem', '-Recurse', '-Force', and credential extensions (.key, .pem, .pfx, id_rsa, .kdbx). Sysmon Event ID 11: File Create for the output file. PowerShell ScriptBlock Log Event ID 4104 with full script.
- Test 3File Search via Windows where.exe for Executable Targets
Expected signal: Sysmon Event ID 1: Process Create with Image=where.exe, CommandLine containing '/r C:\Program Files *.exe'. Security Event ID 4688 with same details if command line auditing is enabled. Sysmon Event ID 11 for the output file creation.
- Test 4Tree Command for Full Filesystem Enumeration
Expected signal: Sysmon Event ID 1: Process Create with Image=cmd.exe, CommandLine containing 'tree /f /a C:\Users'. Security Event ID 4688 if command line auditing is enabled. Sysmon Event ID 11 for the output file creation in TEMP.
- Test 5Linux Credential File Discovery via find
Expected signal: Linux auditd EXECVE records showing find command with -name patterns for credential files. Syslog entries if process accounting is enabled. On systems with Sysmon for Linux: Event ID 1 (Process Create) with CommandLine showing find with credential extension patterns.
References (7)
- https://attack.mitre.org/techniques/T1083/
- https://blogs.jpcert.or.jp/en/2016/01/windows-commands-abused-by-attackers.html
- https://www.us-cert.gov/ncas/alerts/TA18-106A
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1083/T1083.md
- https://learn.microsoft.com/en-us/defender-endpoint/advanced-hunting-deviceprocessevents-table
- https://docs.splunk.com/Documentation/SplunkCloud/latest/SearchReference/CommonStatsFunctions
- https://github.com/SigmaHQ/sigma/tree/master/rules/windows/process_creation
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