Potential RemoteMonologue Attack

 1[metadata]
 2creation_date = "2025/04/14"
 3integration = ["endpoint", "m365_defender", "sentinel_one_cloud_funnel", "windows"]
 4maturity = "production"
 5updated_date = "2025/04/14"
 6min_stack_version = "8.14.0"
 7min_stack_comments = "Breaking change at 8.14.0 for the Windows Integration."
 8
 9[rule]
10author = ["Elastic"]
11description = """
12Identifies attempt to perform session hijack via COM object registry modification by setting the RunAs value to Interactive User.
13"""
14from = "now-9m"
15index = ["logs-endpoint.events.registry-*", "endgame-*", "logs-m365_defender.event-*", "logs-sentinel_one_cloud_funnel.*", "logs-windows.sysmon_operational-*"]
16language = "eql"
17license = "Elastic License v2"
18name = "Potential RemoteMonologue Attack"
19references = [
20    "https://www.ibm.com/think/x-force/remotemonologue-weaponizing-dcom-ntlm-authentication-coercions#1",
21    "https://github.com/xforcered/RemoteMonologue"
22]
23risk_score = 73
24rule_id = "c18975f5-676c-4091-b626-81e8938aa2ee"
25severity = "high"
26tags = [
27    "Domain: Endpoint",
28    "OS: Windows",
29    "Use Case: Threat Detection",
30    "Tactic: Defense Evasion",
31    "Data Source: Elastic Defend",
32    "Data Source: Elastic Endgame",
33    "Data Source: Microsoft Defender for Endpoint",
34    "Data Source: SentinelOne",
35    "Data Source: Sysmon",
36    "Resources: Investigation Guide",
37]
38timestamp_override = "event.ingested"
39type = "eql"
40
41query = '''
42registry where host.os.type == "windows" and event.action != "deletion" and registry.value == "RunAs" and registry.data.strings : "Interactive User"
43'''
44note = """## Triage and analysis
45
46### Investigating Potential RemoteMonologue Attack
47
48
49### Possible investigation steps
50
51- Review the registry event logs to confirm the modification of the RunAs value in the specified registry paths, ensuring the change was not part of a legitimate administrative action.
52- Identify the user account and process responsible for the registry modification by examining the event logs for associated user and process information.
53- Check for any recent remote authentication attempts or sessions on the affected host to determine if this activity is associated with lateral movement or not.
54- Investigate the timeline of the registry change to correlate with any other suspicious activities or alerts on the host, such as the execution of unusual processes or network connections.
55
56
57### False positive analysis
58
59- Software updates or installations that modify COM settings.
60- Automated scripts or management tools that adjust COM configurations.
61### Response and remediation
62
63- Immediately isolate the affected system from the network to prevent further unauthorized access or lateral movement by the adversary.
64- Modify the registry value back to its secure state, ensuring that "RunAs" value is not set to "Interactive User".
65- Conduct a thorough review of recent user activity and system logs to identify any unauthorized access or changes made during the period NLA was disabled.
66- Reset passwords for all accounts that have accessed the affected system to mitigate potential credential compromise.
67- Escalate the incident to the security operations center (SOC) or incident response team for further investigation and to determine if additional systems are affected.
68- Implement enhanced monitoring on the affected system and similar endpoints to detect any further attempts to disable NLA or other suspicious activities.
69"""
70
71
72[[rule.threat]]
73framework = "MITRE ATT&CK"
74[[rule.threat.technique]]
75id = "T1112"
76name = "Modify Registry"
77reference = "https://attack.mitre.org/techniques/T1112/"
78
79[[rule.threat.technique]]
80id = "T1562"
81name = "Impair Defenses"
82reference = "https://attack.mitre.org/techniques/T1562/"
83
84
85[rule.threat.tactic]
86id = "TA0005"
87name = "Defense Evasion"
88reference = "https://attack.mitre.org/tactics/TA0005/"