Detection rules › Sigma

Serial console process spawning CMD shell (via command)

Status
experimental
Severity
high
Log source
product windows, category process_creation
Author
mdecrevoisier
Source
github.com/mdecrevoisier/SIGMA-detection-rules

Detects if an attacker open a privileged CMD shell while accessing to an Azure virtual machine via serial cable.

MITRE ATT&CK coverage

Event coverage

Rule body yaml

title: Serial console process spawning CMD shell (via command)
description: Detects if an attacker open a privileged CMD shell while accessing to an Azure virtual machine via serial cable.
references:
- https://www.mandiant.com/resources/blog/sim-swapping-abuse-azure-serial
tags:
- attack.execution
- attack.t1059.003 # Command and Scripting Interpreter: Windows Command Shell 
author: mdecrevoisier
status: experimental
logsource:
  product: windows
  category: process_creation
detection:
  selection:
    ParentImage|endswith: '\sacsess.exe' # C:\Windows\System32\sacsess.exe 
    Image|endswith: '\cmd.exe'
  condition: selection
falsepositives:
- Virtual machine recovery by administrator
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
  ParentImage|endswith: '\sacsess.exe'
  Image|endswith: '\cmd.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
  • \cmd.exe corpus 130 (sigma 130)
ParentImageends_with
  • \sacsess.exe