Detect Brute Force in IBM QRadar
Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained. Without knowledge of the password for an account or set of accounts, an adversary may systematically guess the password using a repetitive or iterative mechanism. Brute forcing passwords can take place via interaction with a service that will check the validity of those credentials or offline against previously acquired credential data, such as password hashes. Threat actors including Fox Kitten, APT38, APT41, OilRig, and Turla have used brute force techniques against RDP, SSH, SMB, and web services.
MITRE ATT&CK
- Tactic
- Credential Access
- Technique
- T1110 Brute Force
- Canonical reference
- https://attack.mitre.org/techniques/T1110/
QRadar Detection Query
SELECT
LOGSOURCE AS Hostname,
sourceip AS SourceIP,
username AS TargetAccount,
COUNT(*) AS FailedAttempts,
UNIQUECOUNT(username) AS DistinctTargets,
MIN(DATEFORMAT(devicetime, 'yyyy-MM-dd HH:mm:ss')) AS FirstAttempt,
MAX(DATEFORMAT(devicetime, 'yyyy-MM-dd HH:mm:ss')) AS LastAttempt,
CASE
WHEN UNIQUECOUNT(username) > 5 AND COUNT(*) >= 10 THEN 'Password Spray'
WHEN UNIQUECOUNT(username) <= 2 AND COUNT(*) >= 20 THEN 'Account Brute Force'
ELSE 'Brute Force'
END AS AttackPattern
FROM events
WHERE LOGSOURCETYPEID = 12
AND CATEGORYNAME(category) ILIKE '%authentication failed%'
AND LONG("LogonType") IN (3, 10)
AND devicetime > NOW() - 86400000
GROUP BY DATEFORMAT(devicetime, '600000'), LOGSOURCE, sourceip, username
HAVING COUNT(*) >= 10
ORDER BY FailedAttempts DESC
LAST 24 HOURSDetects brute force attacks in QRadar using Windows Security Event Log (LOGSOURCETYPEID 12) authentication failure events filtered to network and remote-interactive logon types. Groups events into 10-minute windows (600000ms bins via DATEFORMAT) per source IP and host, requiring at least 10 failures. Classifies attack pattern as Password Spray (>5 distinct targets) or Account Brute Force (single target, high volume).
Data Sources
Required Tables
False Positives & Tuning
- Vulnerability scanners running credentialed scans (Nessus, Qualys, Rapid7) from a dedicated scanner IP generating bursts of authentication attempts against all in-scope hosts
- Backup or monitoring agents using stale service account credentials after a scheduled password rotation, generating continuous 4625 failures from infrastructure server IPs until credentials are updated
- Network access control (NAC) systems or 802.1X authenticators batching re-authentication requests from multiple devices through a single source IP at policy enforcement intervals
Other platforms for T1110
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 1RDP Brute Force Simulation with Crowbar
Expected signal: On the target Windows host: Security Event ID 4625 (LogonType=10, RemoteInteractive) for each failed attempt, with IpAddress showing the attacker IP. If lockout policy is enabled and threshold exceeded: Event ID 4740 (account locked out). Network logs: multiple TCP connections to port 3389 from attacker IP in rapid succession.
- Test 2SSH Brute Force with Hydra
Expected signal: On the target Linux host: /var/log/auth.log entries 'Failed password for root from <attacker-ip> port <port> ssh2'. If using auditd: type=USER_AUTH msg entries with res=failed. Sysmon for Linux (if deployed): Event ID 3 (network connection) on the attacker side. SIEM via Syslog forwarder: linux_secure sourcetype or syslog with 'Failed password' pattern.
- Test 3Active Directory Password Spray with PowerShell
Expected signal: On Domain Controller: Security Event ID 4625 (LogonType=3, Network) for each failed account, SubStatus 0xC000006D (wrong password) or 0xC000006A (wrong password for correct username). Caller IP address will be the workstation running the spray. Security Event ID 4771 (Kerberos pre-auth failure) if using Kerberos authentication. Timing will show evenly spaced failures 500ms apart — distinctive automated tool pattern.
- Test 4NTLM Brute Force via SMB with CrackMapExec
Expected signal: Target Windows host: Security Event ID 4625 (LogonType=3, Network, AuthenticationPackageName=NTLM) for each failed credential. Domain Controller: Security Event ID 4776 (NTLM authentication attempt, error code 0xC000006A for wrong password) with Workstation field showing attacker hostname. Network: multiple TCP connections to port 445 (SMB) from attacker IP. CME results show [*] for failure and [+] for success in its output.
References (10)
- https://attack.mitre.org/techniques/T1110/
- https://www.microsoft.com/en-us/security/blog/2021/09/27/foggyweb-targeted-nobelium-malware-leads-to-persistent-backdoor/
- https://learn.microsoft.com/en-us/defender-for-identity/compromised-credentials-alerts
- https://learn.microsoft.com/en-us/azure/active-directory/reports-monitoring/reference-sign-ins-error-codes
- https://www.dragos.com/wp-content/uploads/CRASHOVERRIDE2018.pdf
- https://www.trendmicro.com/en_us/research/20/l/pawn-storm-lack-of-sophistication-as-a-strategy.html
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1110/T1110.md
- https://github.com/SigmaHQ/sigma/tree/master/rules/windows/builtin/security
- https://www.cisa.gov/sites/default/files/2024-09/aa24-249a-foreign-threat-actor-conducting-large-scale-spear-phishing-campaign-with-rdp-attachments.pdf
- https://docs.microsoft.com/en-us/windows/security/threat-protection/auditing/event-4625
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