Detect Account Access Removal in Sumo Logic CSE
Adversaries may interrupt availability of system and network resources by inhibiting access to accounts utilized by legitimate users. Accounts may be deleted, locked, or manipulated (changed credentials, revoked permissions) to remove access. In Windows, the Net utility, Set-LocalUser, and Set-ADAccountPassword PowerShell cmdlets may be used to modify user accounts. In Linux, the passwd utility may be used to change passwords. Ransomware families such as LockerGoga, MegaCortex, and Akira use this technique to impede incident response before completing their encryption objective. LAPSUS$ has removed global admin accounts to lock organizations out of all access.
MITRE ATT&CK
- Tactic
- Impact
- Technique
- T1531 Account Access Removal
- Canonical reference
- https://attack.mitre.org/techniques/T1531/
Sumo Detection Query
(_sourceCategory=windows/security OR _sourceCategory=windows/sysmon OR _sourceCategory=linux/secure)
| where (EventID in ("4723", "4724", "4725", "4726", "4740") and !matches(TargetUserName, ".*\\$"))
or (EventID = "1" and (
matches(CommandLine, "(?i).*net[\\s]+user[\\s\\S]+\/del.*")
or matches(CommandLine, "(?i).*Set-LocalUser.*")
or matches(CommandLine, "(?i).*Set-ADAccountPassword.*")
or matches(CommandLine, "(?i).*Disable-ADAccount.*")
or matches(CommandLine, "(?i).*Remove-ADUser.*")
or matches(CommandLine, "(?i).*Remove-LocalUser.*")
or matches(CommandLine, "(?i).*userdel[\\s]+.*")
or matches(CommandLine, "(?i).*usermod[\\s]+-L.*")
))
| eval RiskScore = if(EventID = "4726", 90,
if(matches(CommandLine, "(?i).*(net[\\s]+user.+\/del).*"), 90,
if(matches(CommandLine, "(?i).*(Set-LocalUser|Set-ADAccountPassword|Disable-ADAccount|Remove-ADUser|Remove-LocalUser).*"), 75,
if(EventID = "4725", 70,
if(EventID = "4724", 60,
if(matches(CommandLine, "(?i).*(userdel|usermod[\\s]+-L).*"), 50,
if(EventID = "4723", 40,
if(EventID = "4740", 30, 40))))))))
| eval ActionType = if(EventID = "4726", "AccountDeleted",
if(EventID = "4725", "AccountDisabled",
if(EventID = "4724", "PasswordResetAttempt",
if(EventID = "4723", "PasswordChangeAttempt",
if(EventID = "4740", "AccountLockedOut", "ProcessBasedAccountOp")))))
| eval DetectionNote = if(RiskScore >= 90, "CRITICAL: Account deletion or net user /delete",
if(RiskScore >= 70, "HIGH: Account disabled or PowerShell AD cmdlet",
if(RiskScore >= 50, "MEDIUM: Password reset or Linux account modification",
"LOW: Password change attempt or lockout")))
| sort by RiskScore desc, _messageTime desc
| fields _messageTime, Computer, SubjectUserName, TargetUserName, EventID, ActionType, RiskScore, DetectionNote, CommandLineSumo Logic search query detecting T1531 Account Access Removal across Windows Security Event Log account lifecycle events (4723, 4724, 4725, 4726, 4740), Sysmon EventID 1 process creation events with account manipulation command lines, and Linux authentication log entries. Implements risk scoring from 30 (lockout) to 90 (account deletion) with analyst-facing detection notes for triage. Computer accounts (TargetUserName ending in $) are excluded. Requires Sumo Logic Windows and Linux sources configured with standard _sourceCategory paths.
Data Sources
Required Tables
False Positives & Tuning
- Identity governance platforms (SailPoint, Saviynt, CyberArk) executing automated access review remediations that generate bursts of account disable or delete events — correlate EventID 4726/4725 clusters with change management records to distinguish authorized batch offboarding
- IT service desk personnel performing documented offboarding with active ticketing system entries — build a Sumo Logic lookup table of approved admin SubjectUserName values and suppress matches from that set
- _sourceCategory paths for windows/security, windows/sysmon, and linux/secure vary by deployment — validate with: * | count by _sourceCategory and update the initial source filter to match your environment's actual category taxonomy
Other platforms for T1531
Testing Methodology
Validate this detection against 4 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 1Delete Local Windows User Account via Net Command
Expected signal: Security Event ID 4726 (A user account was deleted) with SubjectUserName=current admin account and TargetUserName=df00techtest. Sysmon Event ID 1 for net.exe and net1.exe with CommandLine containing 'user df00techtest /delete'. Security Event ID 4720 (account created) for the creation step.
- Test 2Disable Local User Account via PowerShell Set-LocalUser
Expected signal: Security Event ID 4725 (A user account was disabled) with TargetUserName=df00techtest2. Sysmon Event ID 1 for powershell.exe with CommandLine containing 'Set-LocalUser' and '-Enabled $false'. PowerShell ScriptBlock Log Event ID 4104 with the full Set-LocalUser command.
- Test 3Bulk Account Password Change Simulation via Net Command
Expected signal: Security Event ID 4723 (password change attempt) and/or 4724 (password reset) for df00techtest3. Sysmon Event ID 1 for net.exe with CommandLine containing 'user df00techtest3 NewL0ckedP@ssw0rd!'. The password value itself will appear in process creation logs if command line auditing is enabled.
- Test 4Linux Account Lock via passwd -l
Expected signal: Linux auditd records: syscall=execve for useradd and passwd commands with argv showing '-l df00techtest_linux'. Syslog entries in /var/log/auth.log or /var/log/secure: 'passwd: password changed for df00techtest_linux'. If auditd is configured with USER_MGMT rules, generates AUDIT_USER_MGMT events for account modification.
References (9)
- https://attack.mitre.org/techniques/T1531/
- https://www.carbonblack.com/2019/03/22/tau-threat-intelligence-notification-lockergoga-ransomware/
- https://unit42.paloaltonetworks.com/born-this-way-origins-of-lockergoga/
- https://web.archive.org/web/20230608061141/https://www.obsidiansecurity.com/blog/saas-ransomware-observed-sharepoint-microsoft-365/
- https://learn.microsoft.com/en-us/windows/security/threat-protection/auditing/event-4726
- https://learn.microsoft.com/en-us/windows/security/threat-protection/auditing/event-4725
- https://learn.microsoft.com/en-us/windows/security/threat-protection/auditing/event-4724
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1531/T1531.md
- https://www.microsoft.com/en-us/security/blog/2022/03/22/dev-0537-criminal-actor-targeting-organizations-for-data-exfiltration-and-destruction/
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