Network Connection via Registration Utility
editNetwork Connection via Registration Utility
editIdentifies the native Windows tools regsvr32.exe, regsvr64.exe, RegSvcs.exe, or RegAsm.exe making a network connection. This may be indicative of an attacker bypassing allowlists or running arbitrary scripts via a signed Microsoft binary.
Rule type: eql
Rule indices:
- winlogbeat-*
- logs-endpoint.events.*
- logs-windows.*
Severity: low
Risk score: 21
Runs every: 5m
Searches indices from: now-9m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Elastic
- Host
- Windows
- Threat Detection
- Execution
Version: 101
Rule authors:
- Elastic
Rule license: Elastic License v2
Rule query
editsequence by process.entity_id
[process where event.type == "start" and
process.name : ("regsvr32.exe", "RegAsm.exe", "RegSvcs.exe") and
not (
(?process.Ext.token.integrity_level_name : "System" or ?winlog.event_data.IntegrityLevel : "System") and
(process.parent.name : "msiexec.exe" or process.parent.executable : ("C:\\Program Files (x86)\\*.exe", "C:\\Program Files\\*.exe"))
)
]
[network where process.name : ("regsvr32.exe", "RegAsm.exe", "RegSvcs.exe") and
not cidrmatch(destination.ip, "10.0.0.0/8", "127.0.0.0/8", "169.254.0.0/16", "172.16.0.0/12", "192.0.0.0/24",
"192.0.0.0/29", "192.0.0.8/32", "192.0.0.9/32", "192.0.0.10/32", "192.0.0.170/32", "192.0.0.171/32",
"192.0.2.0/24", "192.31.196.0/24", "192.52.193.0/24", "192.168.0.0/16", "192.88.99.0/24", "224.0.0.0/4",
"100.64.0.0/10", "192.175.48.0/24","198.18.0.0/15", "198.51.100.0/24", "203.0.113.0/24", "240.0.0.0/4", "::1",
"FE80::/10", "FF00::/8") and network.protocol != "dns"]
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Execution
- ID: TA0002
- Reference URL: https://attack.mitre.org/tactics/TA0002/
-
Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
-
Technique:
- Name: System Binary Proxy Execution
- ID: T1218
- Reference URL: https://attack.mitre.org/techniques/T1218/
-
Sub-technique:
- Name: Regsvr32
- ID: T1218.010
- Reference URL: https://attack.mitre.org/techniques/T1218/010/