Possible DCSync Attack

Title: Possible DCSync Attack
Status: test
Description:Detects remote RPC calls to MS-DRSR from non DC hosts, which could indicate DCSync / DCShadow attacks.
References:
  -https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-drsr/f977faaa-673e-4f66-b9bf-48c640241d47?redirectedfrom=MSDN
  -https://github.com/jsecurity101/MSRPC-to-ATTACK/blob/ddd4608fe8684fcf2fcf9b48c5f0b3c28097f8a3/documents/MS-DRSR.md
  -https://github.com/zeronetworks/rpcfirewall
  -https://zeronetworks.com/blog/stopping-lateral-movement-via-the-rpc-firewall/
Author: Sagie Dulce, Dekel Paz
Date: 2022-01-01
modified:None
Tags:

• -'attack.t1033'
• -'attack.discovery'

Logsource:

• product: rpc_firewall
• category: application
• definition: Requirements: install and apply the RPC Firewall to all processes, enable DRSR UUID (e3514235-4b06-11d1-ab04-00c04fc2dcd2) for "dangerous" opcodes (not 0,1 or 12) only from trusted IPs (DCs)

Detection:
  selection:
    EventLog: 'RPCFW'
    EventID: '3'
    InterfaceUuid: 'e3514235-4b06-11d1-ab04-00c04fc2dcd2'
  filter:
    OpNum:
      -'0'
      -'1'
      -'12'

  condition:selection and not filter
Falsepositives:
  -Unknown
Level: high