""ET CURRENT_EVENTS Inbound PowerShell Executing Base64 Decoded VBE from Temp 2018-11-29""

SID: 2026677

Revision: 2

Class Type: trojan-activity

Metadata: affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2018_11_29, deployment Perimeter, performance_impact Low, signature_severity Major, tag PowerShell, tag Obfuscated, updated_at 2018_11_29

Reference:

Protocol: tcp

Source Network: $EXTERNAL_NET

Source Port: $HTTP_PORTS

Destination Network: $HOME_NET

Destination Port: any

Flow: established,from_server

Contents:

  • Value: "200"

  • Value: "|3a 3a|FromBase64String"

  • Value: "-Path|20|C|3a 5c|windows|5c|temp|5c|"

  • Value: "start-process|20|c|3a 5c|windows|5c|system32|5c|wscript.exe|20|-ArgumentList|20 22|c|3a 5c|windows|5c|temp|5c|"

  • Value: ".vbe|22|"

Within: 20

PCRE:

Special Options:

  • http_stat_code

  • file_data

  • nocase

  • nocase

  • nocase

  • fast_pattern

source