Detection rules › Sigma

Potential Suspicious Browser Launch From Document Reader Process

Severity
medium
Author
Joseph Kamau
Source
upstream

Detects when a browser process or browser tab is launched from an application that handles document files such as Adobe, Microsoft Office, etc. And connects to a web application over http(s), this could indicate a possible phishing attempt.

MITRE ATT&CK coverage

TacticTechniques
ExecutionT1204.002 User Execution: Malicious File

Event coverage

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

Stages and Predicates

Stage 1: selection

or:
Image|endswith: '\brave.exe'
Image|endswith: '\chrome.exe'
Image|endswith: '\firefox.exe'
Image|endswith: '\maxthon.exe'
Image|endswith: '\msedge.exe'
Image|endswith: '\opera.exe'
Image|endswith: '\seamonkey.exe'
Image|endswith: '\vivaldi.exe'
or:
ParentImage|contains: 'Acrobat Reader'
ParentImage|contains: 'Microsoft Office'
ParentImage|contains: 'PDF Reader'
CommandLine|contains: http

Stage 2: not 1 of filter_main_microsoft_help

CommandLine|contains: 'https://go.microsoft.com/fwlink/'

Stage 3: not 1 of filter_optional_foxit

or:
CommandLine|contains: 'http://ad.foxitsoftware.com/adlog.php?'
CommandLine|contains: 'https://globe-map.foxitservice.com/go.php?do=redirect'

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
  • http corpus 31 (sigma 31)
  • http://ad.foxitsoftware.com/adlog.php?
  • https://globe-map.foxitservice.com/go.php?do=redirect
  • https://go.microsoft.com/fwlink/
Imageends_with
  • \brave.exe corpus 20 (sigma 20)
  • \chrome.exe corpus 11 (sigma 11)
  • \firefox.exe corpus 6 (sigma 6)
  • \maxthon.exe corpus 13 (sigma 13)
  • \msedge.exe corpus 22 (sigma 22)
  • \opera.exe corpus 21 (sigma 21)
  • \seamonkey.exe corpus 13 (sigma 13)
  • \vivaldi.exe corpus 19 (sigma 19)
ParentImagematch
  • Acrobat Reader
  • Microsoft Office
  • PDF Reader