detection.wiki

Detection rules › Sigma

Chromium Browser Headless Execution To Mockbin Like Site

Severity
high
Author
X__Junior (Nextron Systems)
Source
upstream

Detects the execution of a Chromium based browser process with the "headless" flag and a URL pointing to the mockbin.org service (which can be used to exfiltrate data).

Event coverage

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

Stages and Predicates

Stage 1: all of selection_img

or:
Image|endswith: '\brave.exe'
Image|endswith: '\chrome.exe'
Image|endswith: '\msedge.exe'
Image|endswith: '\opera.exe'
Image|endswith: '\vivaldi.exe'

Stage 2: all of selection_headless

CommandLine|contains: --headless

Stage 3: all of selection_url

or:
CommandLine|contains: '://mockbin'
CommandLine|contains: '://run.mocky'

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
  • --headless corpus 5 (sigma 5)
  • ://mockbin
  • ://run.mocky
Imageends_with
  • \brave.exe corpus 20 (sigma 20)
  • \chrome.exe corpus 11 (sigma 11)
  • \msedge.exe corpus 22 (sigma 22)
  • \opera.exe corpus 21 (sigma 21)
  • \vivaldi.exe corpus 19 (sigma 19)

Neighbors

Stricter alternatives (narrower than this rule)

The rules below may be useful if you find the current rule is too noisy / lacks specificity.