""ET INFO Suspicious Zipped Filename in Outbound POST Request (Steam_htmlcache.txt)""

SID: 2037091

Revision: 5

Class Type: trojan-activity

Metadata: attack_target Client_Endpoint, created_at 2022_06_22, deployment Perimeter, performance_impact Low, signature_severity Major, tag Stealer, updated_at 2023_08_22, reviewed_at 2024_04_17

Reference:

Protocol: tcp

Source Network: $HOME_NET

Source Port: any

Destination Network: $EXTERNAL_NET

Destination Port: $HTTP_PORTS

Flow: established,to_server

Contents:

  • Value: "POST"

  • Value: "PK|03 04|"

  • Value: "Steam_htmlcache.txt"

Within:

PCRE:

Special Options:

  • http_method

  • http_client_body

  • nocase

  • fast_pattern

  • http_client_body

source