Detectionhightest
Suspicious Serv-U Process Pattern
Detects a suspicious process pattern which could be a sign of an exploited Serv-U service
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Florian Roth (Nextron Systems)Created Wed Jul 14Updated Thu Jul 1458f4ea09-0fc2-4520-ba18-b85c540b0eafwindows
Log Source
WindowsProcess Creation
ProductWindows← raw: windows
CategoryProcess Creation← raw: process_creation
Events generated when a new process is spawned on the system. Covers command-line arguments, parent/child relationships, and process metadata.
Detection Logic
Detection Logic1 selector
detection:
selection:
ParentImage|endswith: '\Serv-U.exe'
Image|endswith:
- '\cmd.exe'
- '\powershell.exe'
- '\pwsh.exe'
- '\wscript.exe'
- '\cscript.exe'
- '\sh.exe'
- '\bash.exe'
- '\schtasks.exe'
- '\regsvr32.exe'
- '\wmic.exe' # https://app.any.run/tasks/c903e9c8-0350-440c-8688-3881b556b8e0/
- '\mshta.exe'
- '\rundll32.exe'
- '\msiexec.exe'
- '\forfiles.exe'
- '\scriptrunner.exe'
condition: selectionFalse Positives
Legitimate uses in which users or programs use the SSH service of Serv-U for remote command execution
References
MITRE ATT&CK
Tactics
Techniques
Other
cve.2021-35211
Rule Metadata
Rule ID
58f4ea09-0fc2-4520-ba18-b85c540b0eaf
Status
test
Level
high
Type
Detection
Created
Wed Jul 14
Modified
Thu Jul 14
Path
rules/windows/process_creation/proc_creation_win_servu_susp_child_process.yml
Raw Tags
attack.credential-accessattack.t1555cve.2021-35211