Remote Encrypting File System Abuse
Detects remote RPC calls to possibly abuse remote encryption service via MS-EFSR
Sigma rule (View on GitHub)
1title: Remote Encrypting File System Abuse
2id: 5f92fff9-82e2-48eb-8fc1-8b133556a551
3status: test
4description: Detects remote RPC calls to possibly abuse remote encryption service via MS-EFSR
5references:
6 - https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-36942
7 - https://github.com/jsecurity101/MSRPC-to-ATTACK/blob/ddd4608fe8684fcf2fcf9b48c5f0b3c28097f8a3/documents/MS-EFSR.md
8 - https://github.com/zeronetworks/rpcfirewall
9 - https://zeronetworks.com/blog/stopping-lateral-movement-via-the-rpc-firewall/
10author: Sagie Dulce, Dekel Paz
11date: 2022-01-01
12tags:
13 - attack.lateral-movement
14logsource:
15 product: rpc_firewall
16 category: application
17 definition: 'Requirements: install and apply the RPC Firewall to all processes with "audit:true action:block uuid:df1941c5-fe89-4e79-bf10-463657acf44d or c681d488-d850-11d0-8c52-00c04fd90f7e'
18detection:
19 selection:
20 EventLog: RPCFW
21 EventID: 3
22 InterfaceUuid:
23 - df1941c5-fe89-4e79-bf10-463657acf44d
24 - c681d488-d850-11d0-8c52-00c04fd90f7e
25 condition: selection
26falsepositives:
27 - Legitimate usage of remote file encryption
28level: high
References
Related rules
- Mstsc.EXE Execution From Uncommon Parent
- Possible Exploitation of Exchange RCE CVE-2021-42321
- Publicly Accessible RDP Service
- Remote File Copy
- Remote Printing Abuse for Lateral Movement