Detection rules › Sigma

Flash Player Update from Suspicious Location

Status
test
Severity
high
Log source
category proxy
Author
Florian Roth (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects a flashplayer update from an unofficial location

MITRE ATT&CK coverage

Rule body yaml

title: Flash Player Update from Suspicious Location
id: 4922a5dd-6743-4fc2-8e81-144374280997
status: test
description: Detects a flashplayer update from an unofficial location
references:
    - https://gist.github.com/roycewilliams/a723aaf8a6ac3ba4f817847610935cfb
author: Florian Roth (Nextron Systems)
date: 2017-10-25
modified: 2022-08-08
tags:
    - attack.initial-access
    - attack.stealth
    - attack.t1189
    - attack.execution
    - attack.t1204.002
    - attack.t1036.005
logsource:
    category: proxy
detection:
    selection:
        - c-uri|contains: '/flash_install.php'
        - c-uri|endswith: '/install_flash_player.exe'
    filter:
        cs-host|endswith: '.adobe.com'
    condition: selection and not filter
falsepositives:
    - Unknown flash download locations
level: high

Stages and Predicates

Stage 0: condition

selection and not filter

Stage 1: selection

selection:
    - c-uri|contains: '/flash_install.php'
    - c-uri|endswith: '/install_flash_player.exe'

Stage 2: not filter

filter:
    cs-host|endswith: '.adobe.com'

Exclusions

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

FieldKindExcluded values
cs-hostends_with.adobe.com

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
c-uriends_with
  • /install_flash_player.exe
c-urimatch
  • /flash_install.php