Detection rules › Sigma

Qakbot Rundll32 Exports Execution

Status
test
Severity
critical
Log source
product windows, category process_creation
Author
X__Junior (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects specific process tree behavior of a "rundll32" execution with exports linked with Qakbot activity.

MITRE ATT&CK coverage

TacticTechniques
ExecutionNo specific technique
StealthNo specific technique

Event coverage

Rule body yaml

title: Qakbot Rundll32 Exports Execution
id: 339ed3d6-5490-46d0-96a7-8abe33078f58
status: test
description: Detects specific process tree behavior of a "rundll32" execution with exports linked with Qakbot activity.
references:
    - https://github.com/pr0xylife/Qakbot/
author: X__Junior (Nextron Systems)
date: 2023-05-24
modified: 2023-05-30
tags:
    - attack.execution
    - detection.emerging-threats
    - attack.stealth
logsource:
    product: windows
    category: process_creation
detection:
    selection_paths:
        ParentImage|endswith:
            # Note: Only add processes seen used by Qakbot to avoid collision with other strains of malware
            - '\cmd.exe'
            - '\cscript.exe'
            - '\curl.exe'
            - '\mshta.exe'
            - '\powershell.exe'
            - '\pwsh.exe'
            - '\wscript.exe'
        Image|endswith: '\rundll32.exe'
        CommandLine|contains:
            # Note: Only add paths seen used by Qakbot to avoid collision with other strains of malware
            - ':\ProgramData\'
            - ':\Users\Public\'
            - '\AppData\Local\Temp\'
            - '\AppData\Roaming\'
    selection_exports:
        CommandLine|endswith:
            # Note: Only add additional exports seen used by Qakbot
            - 'aslr' # https://tria.ge/230524-scgq9add9v/behavioral1#report
            - 'bind'
            - 'DrawThemeIcon'
            - 'GG10'
            - 'GL70'
            - 'jhbvygftr'
            - 'kjhbhkjvydrt'
            - 'LS88'
            - 'Motd'
            - 'N115'
            - 'next' # https://tria.ge/230530-n3rxpahf9w/behavioral2
            - 'Nikn'
            - 'print'
            - 'qqqb'
            - 'qqqq'
            - 'RS32'
            - 'Test'
            - 'Time'
            - 'Updt'
            - 'vips'
            - 'Wind'
            - 'WW50'
            - 'X555'
            - 'XL55'
            - 'xlAutoOpen'
            - 'XS88'
    condition: all of selection_*
falsepositives:
    - Unlikely
level: critical

Stages and Predicates

Stage 0: condition

all of selection_*

Stage 1: selection_paths

selection_paths:
    ParentImage|endswith:
        - '\cmd.exe'
        - '\cscript.exe'
        - '\curl.exe'
        - '\mshta.exe'
        - '\powershell.exe'
        - '\pwsh.exe'
        - '\wscript.exe'
    Image|endswith: '\rundll32.exe'
    CommandLine|contains:
        - ':\ProgramData\'
        - ':\Users\Public\'
        - '\AppData\Local\Temp\'
        - '\AppData\Roaming\'

Stage 2: selection_exports

selection_exports:
    CommandLine|endswith:
        - 'aslr'
        - 'bind'
        - 'DrawThemeIcon'
        - 'GG10'
        - 'GL70'
        - 'jhbvygftr'
        - 'kjhbhkjvydrt'
        - 'LS88'
        - 'Motd'
        - 'N115'
        - 'next'
        - 'Nikn'
        - 'print'
        - 'qqqb'
        - 'qqqq'
        - 'RS32'
        - 'Test'
        - 'Time'
        - 'Updt'
        - 'vips'
        - 'Wind'
        - 'WW50'
        - 'X555'
        - 'XL55'
        - 'xlAutoOpen'
        - 'XS88'

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
CommandLineends_with
  • DrawThemeIcon
  • GG10
  • GL70
  • LS88
  • Motd
  • N115
  • Nikn
  • RS32
  • Test
  • Time
  • Updt
  • WW50
  • Wind
  • X555
  • XL55
  • XS88
  • aslr
  • bind
  • jhbvygftr
  • kjhbhkjvydrt
  • next
  • print
  • qqqb
  • qqqq
  • vips
  • xlAutoOpen
CommandLinematch
  • :\ProgramData\ corpus 9 (sigma 9)
  • :\Users\Public\ corpus 18 (sigma 18)
  • \AppData\Local\Temp\ corpus 26 (sigma 26)
  • \AppData\Roaming\ corpus 16 (sigma 16)
Imageends_with
  • \rundll32.exe corpus 95 (sigma 95)
ParentImageends_with
  • \cmd.exe corpus 20 (sigma 20)
  • \cscript.exe corpus 17 (sigma 17)
  • \curl.exe corpus 3 (sigma 3)
  • \mshta.exe corpus 13 (sigma 13)
  • \powershell.exe corpus 24 (sigma 24)
  • \pwsh.exe corpus 21 (sigma 21)
  • \wscript.exe corpus 19 (sigma 19)