""ET WEB_SERVER Possible WebShell Access Inbound [upload] M1 (CISA AA21-259A)""

SID: 2034009

Revision: 2

Class Type: attempted-user

Metadata: attack_target Server, created_at 2021_09_22, deployment Perimeter, signature_severity Major, tag WebShell, updated_at 2021_09_22, mitre_tactic_id TA0003, mitre_tactic_name Persistence, mitre_technique_id T1505, mitre_technique_name Server_Software_Component

Reference:

Protocol: tcp

Source Network: any

Source Port: any

Destination Network: [$HOME_NET,$HTTP_SERVERS]

Destination Port: any

Flow: established,to_server

Contents:

  • Value: "GET"

  • Value: "?act=upload"

  • Value: "&path="

  • Value: "&context="

Within:

PCRE:

Special Options:

  • http_method

  • http_uri

  • fast_pattern

  • http_uri

  • http_uri

source