Lazarus System Binary Masquerading

Status: test
Severity: high
Log source: category process_creation, product windows
Author: Trent Liffick (@tliffick), Bartlomiej Czyz (@bczyz1)
Source: github.com/SigmaHQ/sigma

Detects binaries used by the Lazarus group which use system names but are executed and launched from non-default location

Known false positives

Unlikely

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1036.005` Masquerading: Match Legitimate Resource Name or Location

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation
Security-Auditing	Event ID 4688: A new process has been created.

Rule body

title: Lazarus System Binary Masquerading
id: 3f7f5b0b-5b16-476c-a85f-ab477f6dd24b
status: test
description: Detects binaries used by the Lazarus group which use system names but are executed and launched from non-default location
references:
    - https://media.kasperskycontenthub.com/wp-content/uploads/sites/43/2018/03/07180244/Lazarus_Under_The_Hood_PDF_final.pdf
author: Trent Liffick (@tliffick), Bartlomiej Czyz (@bczyz1)
date: 2020-06-03
modified: 2023-03-10
tags:
    - attack.stealth
    - attack.t1036.005
    - detection.emerging-threats
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\msdtc.exe'
            - '\gpsvc.exe'
    filter:
        Image|startswith:
            - 'C:\Windows\System32\'
            - 'C:\Windows\SysWOW64\'
    condition: selection and not filter
falsepositives:
    - Unlikely
level: high

Stages and Predicates

Stage 0: `condition`

selection and not filter

Stage 1: `selection`

selection:
    Image|endswith:
        - '\msdtc.exe'
        - '\gpsvc.exe'

Stage 2: `not filter`

filter:
    Image|startswith:
        - 'C:\Windows\System32\'
        - 'C:\Windows\SysWOW64\'

Exclusions

The rule actively suppresses these predicates.

Field	Kind	Excluded values	Search
`Image`	starts_with	`C:\Windows\SysWOW64\`	`excludes:Image` `field:"Image" value:"C:\Windows\SysWOW64\"`
`Image`	starts_with	`C:\Windows\System32\`	`excludes:Image` `field:"Image" value:"C:\Windows\System32\"`

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Image`	ends_with	`\gpsvc.exe` `\msdtc.exe` corpus 2 (sigma 2)	`field:"Image" kind:ends_with`