Detection rules › Sigma

Suspicious Remote Child Process From Outlook

Status
test
Severity
high
Log source
product windows, category process_creation
Author
Markus Neis, Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects a suspicious child process spawning from Outlook where the image is located in a remote location (SMB/WebDav shares).

MITRE ATT&CK coverage

Event coverage

Rule body yaml

title: Suspicious Remote Child Process From Outlook
id: e212d415-0e93-435f-9e1a-f29005bb4723
related:
    - id: 208748f7-881d-47ac-a29c-07ea84bf691d # Outlook Child Processes
      type: similar
status: test
description: Detects a suspicious child process spawning from Outlook where the image is located in a remote location (SMB/WebDav shares).
references:
    - https://github.com/sensepost/ruler
    - https://www.fireeye.com/blog/threat-research/2018/12/overruled-containing-a-potentially-destructive-adversary.html
    - https://speakerdeck.com/heirhabarov/hunting-for-persistence-via-microsoft-exchange-server-or-outlook?slide=49
author: Markus Neis, Nasreddine Bencherchali (Nextron Systems)
date: 2018-12-27
modified: 2023-02-09
tags:
    - attack.execution
    - attack.stealth
    - attack.t1059
    - attack.t1202
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\outlook.exe'
        Image|startswith: '\\\\'
    condition: selection
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    ParentImage|endswith: '\outlook.exe'
    Image|startswith: '\\\\'

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
Imagestarts_with
  • \\\\ corpus 4 (sigma 4)
ParentImageends_with
  • \outlook.exe corpus 5 (sigma 5)