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Detection rules › Sigma

Uncommon Process Access Rights For Target Image

Status
test
Severity
low
Log source
product windows, category process_access
Author
Nasreddine Bencherchali (Nextron Systems), frack113
Source
github.com/SigmaHQ/sigma

Detects process access request to uncommon target images with a "PROCESS_ALL_ACCESS" access mask.

MITRE ATT&CK coverage

TacticTechniques
Privilege EscalationT1055.011 Process Injection: Extra Window Memory Injection
StealthT1055.011 Process Injection: Extra Window Memory Injection

Event coverage

ProviderEventTitle
SysmonEvent ID 10ProcessAccess

Rule body yaml

title: Uncommon Process Access Rights For Target Image
id: a24e5861-c6ca-4fde-a93c-ba9256feddf0
status: test
description: |
    Detects process access request to uncommon target images with a "PROCESS_ALL_ACCESS" access mask.
references:
    - https://learn.microsoft.com/en-us/windows/win32/procthread/process-security-and-access-rights
author: Nasreddine Bencherchali (Nextron Systems), frack113
date: 2024-05-27
tags:
    - attack.privilege-escalation
    - attack.stealth
    - attack.t1055.011
logsource:
    category: process_access
    product: windows
detection:
    selection:
        TargetImage|endswith:
            # Note: Add additional uncommon targets to increase coverage.
            - '\calc.exe'
            - '\calculator.exe'
            - '\mspaint.exe'
            - '\notepad.exe'
            - '\ping.exe'
            - '\wordpad.exe'
            - '\write.exe'
        GrantedAccess: '0x1FFFFF' # PROCESS_ALL_ACCESS - All possible access rights for a process object.
    condition: selection
falsepositives:
    - Unknown
# Note: please upgrade to a higher level after an initial test/tuning.
level: low

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    TargetImage|endswith:
        - '\calc.exe'
        - '\calculator.exe'
        - '\mspaint.exe'
        - '\notepad.exe'
        - '\ping.exe'
        - '\wordpad.exe'
        - '\write.exe'
    GrantedAccess: '0x1FFFFF'

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
GrantedAccesseq
  • 0x1FFFFF corpus 9 (sigma 7, splunk 1, kusto 1)
TargetImageends_with
  • \calc.exe corpus 2 (sigma 2)
  • \calculator.exe corpus 2 (sigma 2)
  • \mspaint.exe corpus 2 (sigma 2)
  • \notepad.exe corpus 2 (sigma 2)
  • \ping.exe corpus 2 (sigma 2)
  • \wordpad.exe corpus 2 (sigma 2)
  • \write.exe corpus 2 (sigma 2)