diff --git a/rules/windows/defense_evasion_regmod_remotemonologue.toml b/rules/windows/defense_evasion_regmod_remotemonologue.toml index 96c01f54f..47d0258a0 100644 --- a/rules/windows/defense_evasion_regmod_remotemonologue.toml +++ b/rules/windows/defense_evasion_regmod_remotemonologue.toml @@ -2,7 +2,7 @@ creation_date = "2025/04/14" integration = ["endpoint", "m365_defender", "sentinel_one_cloud_funnel", "windows"] maturity = "production" -updated_date = "2025/07/02" +updated_date = "2025/08/08" [rule] author = ["Elastic"] @@ -33,11 +33,11 @@ note = """## Triage and analysis - 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. - 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. - ### False positive analysis - Software updates or installations that modify COM settings. - Automated scripts or management tools that adjust COM configurations. + ### Response and remediation - Immediately isolate the affected system from the network to prevent further unauthorized access or lateral movement by the adversary. @@ -51,9 +51,9 @@ references = [ "https://www.ibm.com/think/x-force/remotemonologue-weaponizing-dcom-ntlm-authentication-coercions#1", "https://github.com/xforcered/RemoteMonologue", ] -risk_score = 73 +risk_score = 47 rule_id = "c18975f5-676c-4091-b626-81e8938aa2ee" -severity = "high" +severity = "medium" tags = [ "Domain: Endpoint", "OS: Windows", @@ -70,7 +70,49 @@ timestamp_override = "event.ingested" type = "eql" query = ''' -registry where host.os.type == "windows" and event.action != "deletion" and registry.value == "RunAs" and registry.data.strings : "Interactive User" +registry where host.os.type == "windows" and event.action != "deletion" and + registry.value == "RunAs" and registry.data.strings : "Interactive User" and + + not + ( + ( + process.executable : ( + "C:\\ProgramData\\Microsoft\\Windows Defender\\Platform\\4.*\\MsMpEng.exe", + "C:\\Program Files\\Windows Defender\\MsMpEng.exe" + ) and + registry.path : "*\\SOFTWARE\\Classes\\AppID\\{1111A26D-EF95-4A45-9F55-21E52ADF9887}\\RunAs" + ) or + ( + process.executable : ( + "C:\\Program Files\\TeamViewer\\TeamViewer.exe", + "C:\\Program Files (x86)\\TeamViewer\\TeamViewer.exe" + ) and + registry.path : "*\\SOFTWARE\\Classes\\AppID\\{850A928D-5456-4865-BBE5-42635F1EBCA1}\\RunAs" + ) or + ( + process.executable : "C:\\Windows\\System32\\svchost.exe" and + registry.path : "*\\S-1-*Classes\\AppID\\{D3E34B21-9D75-101A-8C3D-00AA001A1652}\\RunAs" + ) or + ( + process.executable : "C:\\Windows\\System32\\SecurityHealthService.exe" and + registry.path : ( + "*\\SOFTWARE\\Classes\\AppID\\{1D278EEF-5C38-4F2A-8C7D-D5C13B662567}\\RunAs", + "*\\SOFTWARE\\Classes\\AppID\\{7E55A26D-EF95-4A45-9F55-21E52ADF9878}\\RunAs" + ) + ) or + ( + process.executable : "C:\\Windows\\System32\\SecurityHealthService.exe" and + registry.path : ( + "*\\SOFTWARE\\Classes\\AppID\\{1D278EEF-5C38-4F2A-8C7D-D5C13B662567}\\RunAs", + "*\\SOFTWARE\\Classes\\AppID\\{7E55A26D-EF95-4A45-9F55-21E52ADF9878}\\RunAs" + ) + ) or + registry.path : ( + "HKLM\\SOFTWARE\\Microsoft\\Office\\ClickToRun\\VREGISTRY_*", + "\\REGISTRY\\MACHINE\\SOFTWARE\\Microsoft\\Office\\ClickToRun\\VREGISTRY_*" + ) or + (process.executable : "C:\\windows\\System32\\msiexec.exe" and user.id : "S-1-5-18") + ) '''