Detect Abuse Elevation Control Mechanism in Google Chronicle
Adversaries may circumvent mechanisms designed to control elevated privileges to gain higher-level permissions. Most modern systems contain native elevation control mechanisms intended to limit privileges a user can perform. Adversaries exploit these mechanisms across Windows (UAC bypass via auto-elevate binaries, COM object hijacking, DLL side-loading into elevated processes), Linux (setuid/setgid bit abuse, sudo misconfiguration, pkexec exploitation), macOS (TCC database manipulation, Elevated Execution with Prompt), and cloud environments (temporary role assumption, IAM privilege escalation). Real-world actors including UNC3886 and malware like Raspberry Robin have weaponized these techniques to gain SYSTEM or root access without triggering standard UAC consent dialogs.
MITRE ATT&CK
- Technique
- T1548 Abuse Elevation Control Mechanism
- Canonical reference
- https://attack.mitre.org/techniques/T1548/
YARA-L Detection Query
rule uac_bypass_autoelevate_child_spawn {
meta:
author = "Argus Detection Engineering"
description = "Detects UAC bypass via auto-elevate binaries spawning suspicious shell or scripting child processes (T1548.002)"
mitre_attack_tactic = "Privilege Escalation"
mitre_attack_technique = "T1548"
mitre_attack_subtechnique = "T1548.002"
severity = "HIGH"
priority = "HIGH"
confidence = "HIGH"
version = "1.0"
events:
$proc.metadata.event_type = "PROCESS_LAUNCH"
$proc.principal.process.file.full_path = /(?i)(fodhelper|eventvwr|sdclt|cmstp|computerdefaults|slui|wsreset|dccw|pkgmgr|wusa|infdefaultinstall|msconfig|colorcpl|cliconfg|dism|eudcedit|iexpress|ntprint|recdisc)\.exe$/
$proc.target.process.file.full_path = /(?i)(cmd|powershell|pwsh|mshta|wscript|cscript|rundll32|regsvr32|msiexec|certutil|bitsadmin|wmic|regasm|regsvcs)\.exe$/
$proc.principal.hostname = $hostname
condition:
$proc
}
rule uac_bypass_registry_hijack_prep {
meta:
author = "Argus Detection Engineering"
description = "Detects registry key writes to ms-settings or mscfile shell open command paths used in fodhelper/eventvwr UAC bypass (T1548.002)"
mitre_attack_tactic = "Privilege Escalation"
mitre_attack_technique = "T1548"
mitre_attack_subtechnique = "T1548.002"
severity = "CRITICAL"
priority = "HIGH"
confidence = "HIGH"
version = "1.0"
events:
$reg.metadata.event_type = "REGISTRY_MODIFICATION"
(
$reg.target.registry.registry_key = /(?i).*\\Software\\Classes\\ms-settings\\shell\\open\\command.*/ or
$reg.target.registry.registry_key = /(?i).*\\Software\\Classes\\mscfile\\shell\\open\\command.*/
)
$reg.principal.hostname = $hostname
condition:
$reg
}
rule linux_setuid_sudo_privilege_escalation {
meta:
author = "Argus Detection Engineering"
description = "Detects Linux privilege escalation via setuid bit manipulation or interactive sudo shell spawning by non-privileged accounts (T1548.001 / T1548.003)"
mitre_attack_tactic = "Privilege Escalation"
mitre_attack_technique = "T1548"
mitre_attack_subtechnique = "T1548.001"
severity = "HIGH"
priority = "MEDIUM"
confidence = "MEDIUM"
version = "1.0"
events:
$linux.metadata.event_type = "PROCESS_LAUNCH"
$linux.principal.platform = "LINUX"
(
$linux.target.process.command_line = /(?i).*(chmod \+s|chmod u\+s|chmod 4755|chmod 4777|chmod 6755).*/ or
(
$linux.target.process.file.full_path = /(?i).*\/sudo$/ and
$linux.target.process.command_line = /(?i)sudo\s+(-s|su|bash|sh|\/bin\/(bash|sh)|python[23]?|perl|ruby).*/
) or
$linux.target.process.file.full_path = /(?i).*\/(pkexec|doas)$/
)
not $linux.principal.user.userid = "root"
not $linux.principal.user.userid = "daemon"
not $linux.principal.user.userid = "nobody"
$linux.principal.hostname = $hostname
condition:
$linux
}Three complementary Chronicle YARA-L 2.0 rules detecting abuse of elevation control mechanisms (T1548): Rule 1 matches PROCESS_LAUNCH events where a known UAC auto-elevate binary (18 binaries including fodhelper, eventvwr, sdclt, cmstp) spawns a shell or scripting interpreter child process. Rule 2 matches REGISTRY_MODIFICATION events targeting ms-settings or mscfile shell open command paths used in registry-based UAC hijacks. Rule 3 detects Linux setuid bit manipulation and interactive sudo shell invocations by non-system accounts. All rules use UDM field model with principal (parent/actor) and target (child/object) semantics.
Data Sources
Required Tables
False Positives & Tuning
- Authorized IT management tooling that invokes colorcpl.exe, recdisc.exe, or msconfig.exe as part of OS hardening scripts and spawns cmd.exe for configuration validation steps
- Enterprise software packaging tools (WiX, NSIS, InstallShield) that use dism.exe or wusa.exe as parent processes for package extraction, potentially spawning msiexec.exe as a child
- Linux system accounts performing authorized chmod operations on application binaries during deployment pipelines; tune the Linux rule by adding allowlist conditions for known CI/CD service account UIDs
Other platforms for T1548
Testing Methodology
Validate this detection against 5 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Fodhelper UAC Bypass — Registry Staging and Execution
Expected signal: Sysmon Event ID 13 (RegistryValueSet): TargetObject containing HKCU\Software\Classes\ms-settings\shell\open\command, Details showing cmd.exe payload. Sysmon Event ID 1 (Process Create): Image=fodhelper.exe with MandatoryLabel=High Mandatory Level. Sysmon Event ID 1 again: ParentImage=fodhelper.exe, Image=cmd.exe, MandatoryLabel=High Mandatory Level — this is the UAC bypassed child. Security Event ID 4624 may show a new elevated token. MDE DeviceRegistryEvents will show ActionType=RegistryValueSet on the ms-settings key.
- Test 2Eventvwr UAC Bypass — mscfile COM Hijacking
Expected signal: Sysmon Event ID 13: TargetObject=HKCU\Software\Classes\mscfile\shell\open\command, Details=cmd.exe /c whoami /priv... Sysmon Event ID 1: Image=eventvwr.exe with MandatoryLabel=High Mandatory Level. Sysmon Event ID 1: ParentImage=eventvwr.exe, Image=cmd.exe, CommandLine containing whoami /priv, MandatoryLabel=High Mandatory Level. Security Event ID 4688 (if command line auditing enabled) with mandatory label showing High Integrity.
- Test 3Linux Setuid Bit Abuse — Copy Shell and Set SUID
Expected signal: MDE DeviceProcessEvents (Linux): ProcessCommandLine containing 'chmod u+s /tmp/argus-suid-test'. Follow-on process event showing /tmp/argus-suid-test -p -c 'id; whoami' with AccountName of the test runner but effective UID of root in output. Linux audit log (auditd): SYSCALL records for chmod with mode=104755 (setuid+755), PATH record for the target file. /var/log/auth.log: sudo session opened for command /bin/chmod. Sysmon for Linux (if deployed): Event ID 1 showing chmod command, Event ID 1 showing suid binary execution.
- Test 4Sudo GTFOBins Privilege Escalation — Python Breakout
Expected signal: Linux auth.log: sudo session opened for user root by testuser(uid=1000), COMMAND=/usr/bin/python3 -c import os... MDE DeviceProcessEvents (Linux): ProcessCommandLine='sudo python3 -c import os; os.setuid(0); os.system(id && whoami && cat /etc/shadow...' with AccountName=testuser. Auditd: SYSCALL setuid with uid=0 result=success from python3 process. The os.system('cat /etc/shadow') represents credential access following privilege escalation.
- Test 5sdclt UAC Bypass — Folder Shell Command Hijacking
Expected signal: Sysmon Event ID 13: TargetObject=HKCU\Software\Classes\Folder\shell\open\command, Details=cmd.exe /c whoami /groups... Sysmon Event ID 1: Image=sdclt.exe with ProcessCommandLine containing /kickoffelev. Sysmon Event ID 1: ParentImage=sdclt.exe, Image=cmd.exe, MandatoryLabel=High Mandatory Level. MDE DeviceRegistryEvents: ActionType=RegistryValueSet on the Folder\shell\open\command key. If UAC bypass succeeds, whoami /groups output will show 'Mandatory Label\High Mandatory Level Label'.
References (13)
- https://attack.mitre.org/techniques/T1548/
- https://technet.microsoft.com/en-us/itpro/windows/keep-secure/how-user-account-control-works
- https://www.welivesecurity.com/2016/07/06/new-osxkeydnap-malware-hungry-credentials/
- https://blog.fortinet.com/2016/12/16/malicious-macro-bypasses-uac-to-elevate-privilege-for-fareit-malware
- https://www.sudo.ws/
- https://learn.microsoft.com/en-us/defender-endpoint/advanced-hunting-deviceprocessevents-table
- https://learn.microsoft.com/en-us/defender-endpoint/advanced-hunting-deviceregistryevents-table
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1548.002/T1548.002.md
- https://github.com/hfiref0x/UACME
- https://gtfobins.github.io/
- https://enigma0x3.net/2016/08/15/fileless-uac-bypass-using-eventvwr-exe-and-registry-hijacking/
- https://enigma0x3.net/2017/03/14/bypassing-uac-using-app-paths/
- https://posts.specterops.io/a-brief-history-of-uac-bypasses-fce8a6a87b75
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