Outbound Network Connection To Public IP Via Winlogon

 1title: Outbound Network Connection To Public IP Via Winlogon
 2id: 7610a4ea-c06d-495f-a2ac-0a696abcfd3b
 3status: experimental
 4description: Detects a "winlogon.exe" process that initiate network communications with public IP addresses
 5references:
 6    - https://www.microsoft.com/en-us/security/blog/2023/04/11/guidance-for-investigating-attacks-using-cve-2022-21894-the-blacklotus-campaign/
 7author: Christopher Peacock @securepeacock, SCYTHE @scythe_io
 8date: 2023/04/28
 9tags:
10    - attack.defense_evasion
11    - attack.execution
12    - attack.command_and_control
13    - attack.t1218.011
14logsource:
15    category: network_connection
16    product: windows
17detection:
18    selection:
19        Image|endswith: '\winlogon.exe'
20        Initiated: 'true'
21    filter_optional_local_ip:
22        DestinationIp|startswith:
23            - '10.'
24            - '127.'
25            - '172.16.'
26            - '172.17.'
27            - '172.18.'
28            - '172.19.'
29            - '172.20.'
30            - '172.21.'
31            - '172.22.'
32            - '172.23.'
33            - '172.24.'
34            - '172.25.'
35            - '172.26.'
36            - '172.27.'
37            - '172.28.'
38            - '172.29.'
39            - '172.30.'
40            - '172.31.'
41            - '192.168.'
42    condition: selection and not 1 of filter_optional_*
43falsepositives:
44    - Communication to other corporate systems that use IP addresses from public address spaces
45level: medium