""ET POLICY Suspicious Windows Installer UA for non-MSI""

SID: 2038809

Revision: 2

Class Type: policy-violation

Metadata: affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2018_09_14, deployment Perimeter, performance_impact Moderate, signature_severity Major, updated_at 2022_09_13

Reference:

  • md5

  • 8000f557f5e8e256b6bd66c82e02aced

Protocol: tcp

Source Network: $HOME_NET

Source Port: any

Destination Network: $EXTERNAL_NET

Destination Port: $HTTP_PORTS

Flow: established,to_server

Contents:

  • Value: "GET"

  • Value: !".msi"

  • Value: "User-Agent|3a 20|Windows Installer|0d 0a|"

  • Value: !"Referer|3a|"

Within:

PCRE:

Special Options:

  • http_method

  • http_uri

  • http_header

  • fast_pattern

  • http_header

source