""ET WEB_CLIENT Exchange Webshell CnC Domain in DNS Lookup""

SID: 2032345

Revision: 2

Class Type: attempted-admin

Metadata: created_at 2021_03_29, updated_at 2021_03_29

Reference:

Protocol: udp

Source Network: $HOME_NET

Source Port: any

Destination Network: any

Destination Port: 53

Flow:

Contents:

  • Value: "|01|" Depth: 1 Offset: 2

  • Value: "|00 01 00 00 00 00 00|"

  • Value: "|05|brian|0f|krebsonsecurity|03|top|00|"

Within: 27

PCRE:

Special Options:

  • nocase

  • fast_pattern

source