detection.wiki

Detection rules › Sigma

Suspicious Serv-U Process Pattern

Severity
high
Author
Florian Roth (Nextron Systems)
Source
upstream

Detects a suspicious process pattern which could be a sign of an exploited Serv-U service

MITRE ATT&CK coverage

TacticTechniques
Credential AccessT1555 Credentials from Password Stores

Event coverage

ProviderEvent IDTitle
Sysmon1Process creation
Security-Auditing4688A new process has been created.

Stages and Predicates

Stage 1: selection

or:
Image|endswith: '\bash.exe'
Image|endswith: '\cmd.exe'
Image|endswith: '\cscript.exe'
Image|endswith: '\forfiles.exe'
Image|endswith: '\mshta.exe'
Image|endswith: '\msiexec.exe'
Image|endswith: '\powershell.exe'
Image|endswith: '\pwsh.exe'
Image|endswith: '\regsvr32.exe'
Image|endswith: '\rundll32.exe'
Image|endswith: '\schtasks.exe'
Image|endswith: '\scriptrunner.exe'
Image|endswith: '\sh.exe'
Image|endswith: '\wmic.exe'
Image|endswith: '\wscript.exe'
ParentImage|endswith: '\Serv-U.exe'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Imageends_with
  • \bash.exe corpus 17 (sigma 17)
  • \cmd.exe corpus 92 (sigma 92)
  • \cscript.exe corpus 64 (sigma 64)
  • \forfiles.exe corpus 11 (sigma 11)
  • \mshta.exe corpus 57 (sigma 57)
  • \msiexec.exe corpus 21 (sigma 21)
  • \powershell.exe corpus 143 (sigma 143)
  • \pwsh.exe corpus 140 (sigma 140)
  • \regsvr32.exe corpus 57 (sigma 57)
  • \rundll32.exe corpus 76 (sigma 76)
  • \schtasks.exe corpus 45 (sigma 45)
  • \scriptrunner.exe corpus 8 (sigma 8)
  • \sh.exe corpus 13 (sigma 13)
  • \wmic.exe corpus 37 (sigma 37)
  • \wscript.exe corpus 64 (sigma 64)
ParentImageends_with
  • \Serv-U.exe