XQL query for hunting MS-DFSNM

[RFeyertag]

Hello dear community, 

has anyone of you a XQL Query for this type of attack?

https://www.bleepingcomputer.com/news/microsoft/new-dfscoerce-ntlm-relay-attack-allows-windows-domai...

BR

Rob

[mfakhouri]

Hi @RFeyertag!

Thank you for submitting the coverage request regarding DFSCoerce.

At this time, our security engineers are working diligently to provide protection and coverage against the DFSCoerce NTLM Relay Attack for the Cortex XDR agent and Cortex XDR server. If you would like to receive direct notifications when advances in this coverage have been deployed or want a more immediate option for inquiries on future attack coverage, we highly recommend contacting our TAC team at https://support.paloaltonetworks.com/. We can update you on the availability of Cortex XDR coverage in the LiveCommunity when it is available, however, that would be best effort and may involve some delay.

[mfakhouri]

Hi @RFeyertag

With the release of Content Update 590-96665, a new XQL query has been provided for the DFSCoerce attack:

dataset  = xdr_data 

| alter day = extract_time(_time, "DAY"), dfs_relay_server = json_extract_scalar(action_rpc_func_str_call_fields,"$.ServerName"), 

 dfs_root_share = json_extract_scalar(action_rpc_func_str_call_fields,"$.RootShare")

| filter event_type = 22 and action_rpc_interface_uuid = "{4FC742E0-4A10-11CF-8273-00AA004AE673}" and action_rpc_func_name  = "NetrDfsRemoveStdRoot" and action_rpc_func_opnum in (12, 13)

| fields actor_remote_ip, agent_hostname, agent_id, action_rpc_func_opnum, action_rpc_func_str_call_fields, action_rpc_func_name, actor_type, day, dfs_relay_server, dfs_root_share

| comp count_distinct(day) as day_count_dfrpc_src_dst_func by actor_type, action_rpc_func_name, action_rpc_func_opnum, agent_hostname, agent_id, actor_remote_ip, dfs_relay_server, dfs_root_share

| filter day_count_dfrpc_src_dst_func < 7

Since the RPC functionality can be normal... this may require further tuning for your environment.

The client can see the remote actor under actor_remote_ip , the affected server under agent_id or agent_hostname , and the possible relay server extracted under dfs_relay_server in addition to other fields there that might help triage.

This is not guaranteed to be the attack, but will most likely show an unusual usage of DFS which can indicate a possible attack.