Detection rules › Sigma

Process Execution From A Potentially Suspicious Folder

Severity
high
Author
Florian Roth (Nextron Systems), Tim Shelton
Source
upstream

Detects a potentially suspicious execution from an uncommon folder.

MITRE ATT&CK coverage

TacticTechniques
Defense EvasionT1036 Masquerading

Event coverage

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

Stages and Predicates

Stage 1: selection

or:
Image|contains: '$Recycle.bin'
Image|contains: ':\Perflogs\'
Image|contains: ':\Users\All Users\'
Image|contains: ':\Users\Default\'
Image|contains: ':\Users\NetworkService\'
Image|contains: ':\Windows\Fonts\'
Image|contains: ':\Windows\Help\'
Image|contains: ':\Windows\IME\'
Image|contains: ':\Windows\Media\'
Image|contains: ':\Windows\System32\Tasks\'
Image|contains: ':\Windows\Tasks\'
Image|contains: ':\Windows\addins\'
Image|contains: ':\Windows\debug\'
Image|contains: ':\Windows\repair\'
Image|contains: ':\Windows\security\'
Image|contains: '\Intel\Logs\'
Image|contains: '\RSA\MachineKeys\'
Image|contains: '\config\systemprofile\'

Stage 2: not 1 of filter_optional_*

or:
Image|endswith: '\CitrixReceiverUpdater.exe'
Image|startswith: 'C:\Windows\SysWOW64\config\systemprofile\Citrix\UpdaterBinaries\'
Image|startswith: 'C:\Users\Public\IBM\ClientSolutions\Start_Programs\'

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
  • \CitrixReceiverUpdater.exe
Imagematch
  • $Recycle.bin
  • :\Perflogs\ corpus 7 (sigma 7)
  • :\Users\All Users\
  • :\Users\Default\ corpus 3 (sigma 3)
  • :\Users\NetworkService\
  • :\Windows\Fonts\ corpus 3 (sigma 3)
  • :\Windows\Help\
  • :\Windows\IME\ corpus 3 (sigma 3)
  • :\Windows\Media\
  • :\Windows\System32\Tasks\ corpus 4 (sigma 4)
  • :\Windows\Tasks\ corpus 5 (sigma 5)
  • :\Windows\addins\
  • :\Windows\debug\
  • :\Windows\repair\
  • :\Windows\security\
  • \Intel\Logs\
  • \RSA\MachineKeys\
  • \config\systemprofile\ corpus 4 (sigma 4)
Imagestarts_with
  • C:\Users\Public\IBM\ClientSolutions\Start_Programs\
  • C:\Windows\SysWOW64\config\systemprofile\Citrix\UpdaterBinaries\