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Service execution or recovery registry value rewritten

Siemphony@siemphonylowT1574.011unverified
AN1195's `MonitoredServiceKeys` knob names `ImagePath`, `ServiceDll`, `FailureCommand` and the `Parameters` subkey as the values a weak ACL lets an attacker rewrite to redirect what a service launches; this rule matches a registry write under `CurrentControlSet\Services\` to any of those value names. The brief's `sigmaLogsource` for this leg is `registry_set` with no `service` qualifier, which is Sysmon's EventID 13 shape (`TargetObject` carries the full key-plus-value path, `Details` carries the written data), and that is the vocabulary this rule is written in. The brief also lists Security EventID 4657 for the same analytic, but 4657 is a structurally different feed — it splits the key and value into separate `ObjectName` and `ObjectValueName` fields rather than Sysmon's single `TargetObject` — so turning on *Audit Registry* and a SACL on the Services key would not make this rule see anything; it would need its own field mapping. The System 7040 leg (service start-type changed) is a different signal again — a configuration change surfaced by the Service Control Manager, not the registry write itself — and is likewise not combined here. This rule cannot express AN1195's `BaselineServiceConfig` or `TimeWindow` knobs: comparing a new value against a known-good baseline, or correlating the write with the service process that starts afterward, both need state or a cross-event join lib/sigma does not model, so a hit is evidence of a rewrite and not by itself evidence that the new value is wrong. Sysmon is not installed by default, and most shipped configurations exclude the high-volume `Services` subtree from EventID 13 entirely — on such a host this rule returns zero rows, which reads as quiet but means blind. UNVERIFIED AS AUTHORED — derived from MITRE ATT&CK DET0427, not hand-written and not tested by its author. Any lab result is on this rule's own page.Full description

The detection

The 4 SIEM queries below are previews produced by Siemphony’s own translator, not pySigma, and none has been executed against a real backend — review before you deploy.

detection.yml

Sentinel · KQL

Run this as a search.

DeviceRegistryEvents| where (RegistryKey contains "\\CurrentControlSet\\Services\\" and (RegistryKey endswith "\\ImagePath" or RegistryKey endswith "\\FailureCommand" or RegistryKey endswith "\\Parameters\\ServiceDll"))

Splunk · SPL

Run this as a search.

index=* (TargetObject="*\\CurrentControlSet\\Services\\*" AND (TargetObject="*\\ImagePath" OR TargetObject="*\\FailureCommand" OR TargetObject="*\\Parameters\\ServiceDll"))

Elastic · ES|QL

Run this as a search.

FROM logs-*| WHERE (TO_LOWER(registry.path) LIKE "*\\\\currentcontrolset\\\\services\\\\*" AND (TO_LOWER(registry.path) LIKE "*\\\\imagepath" OR TO_LOWER(registry.path) LIKE "*\\\\failurecommand" OR TO_LOWER(registry.path) LIKE "*\\\\parameters\\\\servicedll"))

Wazuh · XML rule

Deploy to your manager — this is a rule, not a search.

<group name="sigma,windows,registry_set,">  <!-- Rule ids must be unique on your manager; 100000+ is the user range. -->  <rule id="100000" level="5">    <!-- Set <if_sid> to the decoder/base rule for windows so this only evaluates relevant events. -->    <field name="TargetObject" type="pcre2">(?i)\\CurrentControlSet\\Services\\</field>    <field name="TargetObject" type="pcre2">(?i)(\\ImagePath$|\\FailureCommand$|\\Parameters\\ServiceDll$)</field>    <description>Service execution or recovery registry value rewritten</description>    <mitre>      <id>T1574.011</id>    </mitre>  </rule></group>

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