Detection rules › Sigma

Winlogon process contact to C2 - Blacklotus (Sysmon)

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

Detects Blacklotus HTTP downloader injection into winlogon.exe process.

MITRE ATT&CK coverage

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

title: Winlogon process contact to C2 - Blacklotus (Sysmon)
description: Detects Blacklotus HTTP downloader injection into winlogon.exe process.
requirements: SYSMON configuration from SwiftOnSecurity needs to be adapted in order to audit winlogon.exe connections.
references:
- https://www.microsoft.com/en-us/security/blog/2023/04/11/guidance-for-investigating-attacks-using-cve-2022-21894-the-blacklotus-campaign/
tags:
- attack.command_and_control
- attack.discovery
- attack.t1016 # System Network Configuration Discovery 
author: mdecrevoisier
status: experimental
logsource:
  product: windows
  category: process_creation
detection:
  selection:
    Image|endswith: '\winlogon.exe'
    DestinationPort: 80
  condition: selection
falsepositives:
- None 
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
  Image|endswith: '\winlogon.exe'
  DestinationPort: 80

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
DestinationPorteq
  • 80 corpus 10 (sigma 6, elastic 2, kusto 2)
Imageends_with
  • \winlogon.exe corpus 6 (sigma 6)