Detection rules › Sigma

Unusual Child Process of dns.exe

Status
test
Severity
high
Log source
product windows, category process_creation
Author
Tim Rauch, Elastic (idea)
Source
github.com/SigmaHQ/sigma

Detects an unexpected process spawning from dns.exe which may indicate activity related to remote code execution or other forms of exploitation as seen in CVE-2020-1350 (SigRed)

MITRE ATT&CK coverage

TacticTechniques
Initial AccessT1133 External Remote Services
PersistenceT1133 External Remote Services

Event coverage

Rule body yaml

title: Unusual Child Process of dns.exe
id: a4e3d776-f12e-42c2-8510-9e6ed1f43ec3
status: test
description: Detects an unexpected process spawning from dns.exe which may indicate activity related to remote code execution or other forms of exploitation as seen in CVE-2020-1350 (SigRed)
references:
    - https://www.elastic.co/guide/en/security/current/unusual-child-process-of-dns-exe.html
author: Tim Rauch, Elastic (idea)
date: 2022-09-27
modified: 2023-02-05
tags:
    - attack.persistence
    - attack.initial-access
    - attack.t1133
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\dns.exe'
    filter:
        Image|endswith: '\conhost.exe'
    condition: selection and not filter
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection and not filter

Stage 1: selection

selection:
    ParentImage|endswith: '\dns.exe'

Stage 2: not filter

filter:
    Image|endswith: '\conhost.exe'

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
Imageends_with\conhost.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
ParentImageends_with
  • \dns.exe