Detect Cloud Accounts in Splunk
Valid cloud accounts may be leveraged by adversaries to achieve Initial Access, Persistence, Privilege Escalation, or Defense Evasion in cloud environments. Adversaries may obtain cloud credentials through phishing, brute force, credential theft from endpoints, or by compromising on-premises identity infrastructure federated with cloud services. Once in possession of valid credentials, adversaries can authenticate to cloud management planes (Azure, AWS, GCP), SaaS applications (Microsoft 365, Google Workspace), or identity providers (Entra ID, Okta) and operate as legitimate users. Techniques include abusing service principals, managed identities, OAuth tokens, and API keys to maintain persistence and move laterally across cloud resources.
MITRE ATT&CK
- Technique
- T1078 Valid Accounts
- Sub-technique
- T1078.004 Cloud Accounts
- Canonical reference
- https://attack.mitre.org/techniques/T1078/004/
SPL Detection Query
index=azure_monitor_aad sourcetype="azure:monitor:aad" category="SignInLogs"
| spath output=ResultType path=properties.status.errorCode
| spath output=UserPrincipalName path=properties.userPrincipalName
| spath output=AppDisplayName path=properties.appDisplayName
| spath output=IPAddress path=properties.ipAddress
| spath output=ClientApp path=properties.clientAppUsed
| spath output=Country path=properties.location.countryOrRegion
| spath output=City path=properties.location.city
| spath output=RiskLevel path=properties.riskLevelDuringSignIn
| spath output=AuthRequirement path=properties.authenticationRequirement
| spath output=ConditionalAccess path=properties.conditionalAccessStatus
| spath output=UserAgent path=properties.userAgent
| where ResultType="0"
| eval IsLegacyAuth=if(match(lower(ClientApp), "(imap|pop3|smtp|basicauth|exchange activesync|autodiscover|exchange web services|authenticated smtp|outlook anywhere)"), 1, 0)
| eval IsSuspiciousCountry=if(Country IN ("KP", "IR", "RU", "CN", "BY"), 1, 0)
| eval IsHighRisk=if(RiskLevel IN ("high", "medium"), 1, 0)
| eval IsMFABypassed=if(AuthRequirement="singleFactorAuthentication" AND ConditionalAccess!="notApplied", 1, 0)
| eval RiskScore=IsLegacyAuth + IsSuspiciousCountry + IsHighRisk + IsMFABypassed
| where RiskScore > 0
| eval RiskFactors=mvappend(
if(IsLegacyAuth=1, "LegacyAuth", null()),
if(IsSuspiciousCountry=1, "SuspiciousCountry:".Country, null()),
if(IsHighRisk=1, "HighRisk:".RiskLevel, null()),
if(IsMFABypassed=1, "MFABypassed", null())
)
| table _time, UserPrincipalName, AppDisplayName, IPAddress, Country, City, ClientApp, RiskFactors, RiskScore, AuthRequirement, ConditionalAccess, UserAgent
| sort - RiskScore _timeDetects suspicious cloud account sign-in patterns from Azure AD / Microsoft Entra ID logs ingested into Splunk via Azure Monitor. Evaluates each successful sign-in event against four risk dimensions: legacy authentication protocol usage, sign-in from a high-risk country, Identity Protection risk level of high or medium, and MFA bypass when conditional access policies are applied. A composite risk score enables prioritization, with higher scores indicating multiple concurrent risk factors. Analysts should adjust the country list and risk thresholds based on their organization's user base and travel patterns.
Data Sources
Required Sourcetypes
False Positives & Tuning
- Legitimate business travelers or remote workers authenticating from foreign countries
- Legacy applications using basic authentication that have not yet been migrated to modern auth protocols
- VPN or proxy infrastructure causing geographic misattribution of sign-in source
- Shared service accounts used by automation pipelines from multiple data center IPs
- Break-glass or emergency access accounts used during major incidents from non-standard locations
Other platforms for T1078.004
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 1Azure CLI Authentication with Compromised Credentials
Expected signal: Entra ID SigninLogs: successful interactive sign-in with AppDisplayName='Microsoft Azure CLI', DeviceDetail showing unregistered device, IPAddress of test machine. AuditLogs may show directory read operations. Risk signals may trigger if this is a new location or device for the account.
- Test 2Service Principal Authentication and Enumeration
Expected signal: AADServicePrincipalSignInLogs: service principal authentication event with IPAddress, ResourceDisplayName, and AppId. AuditLogs: directory read operations. If run from a new IP, this will appear as an anomalous source for the service principal.
- Test 3Legacy Authentication Simulation via SMTP Basic Auth
Expected signal: Entra ID SigninLogs: sign-in attempt with ClientAppUsed='Authenticated SMTP' or 'SMTP Auth', Protocol='SMTP', IsInteractive=false. The sign-in will be flagged as legacy authentication. If successful, ResultType=0; if legacy auth is blocked by CA policy, ResultType will reflect the block.
- Test 4Impossible Travel Simulation via Azure Resource Manager API
Expected signal: Two sign-in events in SigninLogs from different IP addresses and geolocations for the same account within a short time window. Entra ID Identity Protection may generate an 'Impossible travel' or 'Unfamiliar sign-in properties' risk detection (AADUserRiskEvents). The second sign-in will have a different CountryOrRegion in LocationDetails.
- Test 5Add Credentials to Existing Service Principal (Persistence)
Expected signal: AuditLogs: OperationName='Add service principal credentials' or 'Update application – Certificates and secrets management' with the initiating user's UPN, source IP, and target service principal name and ID. This is the exact pattern hunted by the Service Principal Credential Addition hunting query.
References (12)
- https://attack.mitre.org/techniques/T1078/004/
- https://learn.microsoft.com/en-us/entra/identity/monitoring-health/concept-sign-ins
- https://learn.microsoft.com/en-us/entra/id-protection/overview-identity-protection
- https://www.microsoft.com/security/blog/2020/12/21/advice-for-incident-responders-on-recovery-from-systemic-identity-compromises/
- https://posts.specterops.io/managed-identity-attack-paths-part-1-automation-accounts-82667d17187a
- https://www.mandiant.com/resources/blog/apt29-microsoft-365
- https://learn.microsoft.com/en-us/azure/sentinel/detect-threats-built-in
- https://github.com/BloodHoundAD/ROADtools
- https://github.com/RhinoSecurityLabs/pacu
- https://learn.microsoft.com/en-us/entra/identity/conditional-access/block-legacy-authentication
- https://learn.microsoft.com/en-us/azure/active-directory/develop/howto-create-service-principal-portal
- https://microsoft.github.io/Microsoft-365-Defender-Hunting-Queries/
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