detection.wiki

Detection rules › Sigma

Suspicious Electron Application Child Processes

Severity
medium
Author
Nasreddine Bencherchali (Nextron Systems)
Source
upstream

Detects suspicious child processes of electron apps (teams, discord, slack, etc.). This could be a potential sign of ".asar" file tampering (See reference section for more information) or binary execution proxy through specific CLI arguments (see related rule)

Event coverage

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

Stages and Predicates

Stage 1: selection_parent

or:
ParentImage|endswith: '\GitHubDesktop.exe'
ParentImage|endswith: '\chrome.exe'
ParentImage|endswith: '\discord.exe'
ParentImage|endswith: '\keybase.exe'
ParentImage|endswith: '\msedge.exe'
ParentImage|endswith: '\msedgewebview2.exe'
ParentImage|endswith: '\msteams.exe'
ParentImage|endswith: '\slack.exe'
ParentImage|endswith: '\teams.exe'

Stage 2: 1 of selection_child_image

or:
Image|endswith: '\cmd.exe'
Image|endswith: '\cscript.exe'
Image|endswith: '\mshta.exe'
Image|endswith: '\powershell.exe'
Image|endswith: '\pwsh.exe'
Image|endswith: '\regsvr32.exe'
Image|endswith: '\whoami.exe'
Image|endswith: '\wscript.exe'

Stage 3: 1 of selection_child_paths

or:
Image|contains: ':\ProgramData\'
Image|contains: ':\Temp\'
Image|contains: '\AppData\Local\Temp\'
Image|contains: '\Users\Public\'
Image|contains: '\Windows\Temp\'

Stage 4: not 1 of filter_optional_discord

CommandLine|contains: '\NVSMI\nvidia-smi.exe'
Image|endswith: '\cmd.exe'
ParentImage|endswith: '\Discord.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
CommandLinematch
  • \NVSMI\nvidia-smi.exe
Imageends_with
  • \cmd.exe corpus 92 (sigma 92)
  • \cscript.exe corpus 64 (sigma 64)
  • \mshta.exe corpus 57 (sigma 57)
  • \powershell.exe corpus 143 (sigma 143)
  • \pwsh.exe corpus 140 (sigma 140)
  • \regsvr32.exe corpus 57 (sigma 57)
  • \whoami.exe corpus 18 (sigma 18)
  • \wscript.exe corpus 64 (sigma 64)
Imagematch
  • :\ProgramData\ corpus 3 (sigma 3)
  • :\Temp\ corpus 12 (sigma 12)
  • \AppData\Local\Temp\ corpus 9 (sigma 9)
  • \Users\Public\ corpus 8 (sigma 8)
  • \Windows\Temp\ corpus 7 (sigma 7)
ParentImageends_with
  • \Discord.exe
  • \GitHubDesktop.exe
  • \chrome.exe corpus 4 (sigma 4)
  • \discord.exe
  • \keybase.exe
  • \msedge.exe corpus 3 (sigma 3)
  • \msedgewebview2.exe
  • \msteams.exe
  • \slack.exe
  • \teams.exe