Remotely Started Services via RPC

  1[metadata]
  2creation_date = "2020/11/16"
  3integration = ["endpoint", "windows"]
  4maturity = "production"
  5updated_date = "2024/04/08"
  6min_stack_comments = "New fields added: required_fields, related_integrations, setup"
  7min_stack_version = "8.3.0"
  8
  9[transform]
 10[[transform.osquery]]
 11label = "Osquery - Retrieve DNS Cache"
 12query = "SELECT * FROM dns_cache"
 13
 14[[transform.osquery]]
 15label = "Osquery - Retrieve All Services"
 16query = "SELECT description, display_name, name, path, pid, service_type, start_type, status, user_account FROM services"
 17
 18[[transform.osquery]]
 19label = "Osquery - Retrieve Services Running on User Accounts"
 20query = """
 21SELECT description, display_name, name, path, pid, service_type, start_type, status, user_account FROM services WHERE
 22NOT (user_account LIKE '%LocalSystem' OR user_account LIKE '%LocalService' OR user_account LIKE '%NetworkService' OR
 23user_account == null)
 24"""
 25
 26[[transform.osquery]]
 27label = "Osquery - Retrieve Service Unsigned Executables with Virustotal Link"
 28query = """
 29SELECT concat('https://www.virustotal.com/gui/file/', sha1) AS VtLink, name, description, start_type, status, pid,
 30services.path FROM services JOIN authenticode ON services.path = authenticode.path OR services.module_path =
 31authenticode.path JOIN hash ON services.path = hash.path WHERE authenticode.result != 'trusted'
 32"""
 33
 34
 35[rule]
 36author = ["Elastic"]
 37description = """
 38Identifies remote execution of Windows services over remote procedure call (RPC). This could be indicative of lateral
 39movement, but will be noisy if commonly done by administrators.
 40"""
 41from = "now-9m"
 42index = ["logs-endpoint.events.process-*", "logs-endpoint.events.network-*", "winlogbeat-*", "logs-windows.sysmon_operational-*"]
 43language = "eql"
 44license = "Elastic License v2"
 45name = "Remotely Started Services via RPC"
 46note = """## Triage and analysis
 47
 48### Investigating Remotely Started Services via RPC
 49
 50The Service Control Manager Remote Protocol is a client/server protocol used for configuring and controlling service programs running on a remote computer. A remote service management session begins with the client initiating the connection request to the server. If the server grants the request, the connection is established. The client can then make multiple requests to modify, query the configuration, or start and stop services on the server by using the same session until the session is terminated.
 51
 52This rule detects the remote creation or start of a service by correlating a `services.exe` network connection and the spawn of a child process.
 53
 54> **Note**:
 55> This investigation guide uses the [Osquery Markdown Plugin](https://www.elastic.co/guide/en/security/master/invest-guide-run-osquery.html) introduced in Elastic Stack version 8.5.0. Older Elastic Stack versions will display unrendered Markdown in this guide.
 56
 57#### Possible investigation steps
 58
 59- Review login events (e.g., 4624) in the alert timeframe to identify the account used to perform this action. Use the `source.address` field to help identify the source system.
 60- Review network events from the source system using the source port identified on the alert and try to identify the program used to initiate the action.
 61- Investigate the process execution chain (parent process tree) for unknown processes. Examine their executable files for prevalence, whether they are located in expected locations, and if they are signed with valid digital signatures.
 62- Investigate any abnormal behavior by the subject process such as network connections, registry or file modifications, and any spawned child processes.
 63- Investigate other alerts associated with the user/host during the past 48 hours.
 64- Validate if the activity is not related to planned patches, updates, network administrator activity, or legitimate software installations.
 65- Examine the host for derived artifacts that indicate suspicious activities:
 66  - Analyze the process executable using a private sandboxed analysis system.
 67  - Observe and collect information about the following activities in both the sandbox and the alert subject host:
 68    - Attempts to contact external domains and addresses.
 69      - Use the Elastic Defend network events to determine domains and addresses contacted by the subject process by filtering by the process' `process.entity_id`.
 70      - Examine the DNS cache for suspicious or anomalous entries.
 71        - $osquery_0
 72    - Use the Elastic Defend registry events to examine registry keys accessed, modified, or created by the related processes in the process tree.
 73    - Examine the host services for suspicious or anomalous entries.
 74      - $osquery_1
 75      - $osquery_2
 76      - $osquery_3
 77  - Retrieve the files' SHA-256 hash values using the PowerShell `Get-FileHash` cmdlet and search for the existence and reputation of the hashes in resources like VirusTotal, Hybrid-Analysis, CISCO Talos, Any.run, etc.
 78- Investigate potentially compromised accounts. Analysts can do this by searching for login events (for example, 4624) to the target host after the registry modification.
 79
 80
 81### False positive analysis
 82
 83- Remote management software like SCCM may trigger this rule. If noisy on your environment, consider adding exceptions.
 84
 85### Response and remediation
 86
 87- Initiate the incident response process based on the outcome of the triage.
 88- Isolate the involved hosts to prevent further post-compromise behavior.
 89- If the triage identified malware, search the environment for additional compromised hosts.
 90  - Implement temporary network rules, procedures, and segmentation to contain the malware.
 91  - Stop suspicious processes.
 92  - Immediately block the identified indicators of compromise (IoCs).
 93  - Inspect the affected systems for additional malware backdoors like reverse shells, reverse proxies, or droppers that attackers could use to reinfect the system.
 94- Remove and block malicious artifacts identified during triage.
 95- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords for these accounts and other potentially compromised credentials, such as email, business systems, and web services.
 96- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.
 97- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.
 98- Using the incident response data, update logging and audit policies to improve the mean time to detect (MTTD) and the mean time to respond (MTTR).
 99"""
100references = [
101    "https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-scmr/705b624a-13de-43cc-b8a2-99573da3635f",
102]
103risk_score = 47
104rule_id = "aa9a274d-6b53-424d-ac5e-cb8ca4251650"
105severity = "medium"
106tags = ["Domain: Endpoint", "OS: Windows", "Use Case: Threat Detection", "Tactic: Lateral Movement", "Resources: Investigation Guide", "Data Source: Elastic Defend", "Data Source: Sysmon"]
107type = "eql"
108
109query = '''
110sequence with maxspan=1s
111   [network where host.os.type == "windows" and process.name : "services.exe" and
112      network.direction : ("incoming", "ingress") and network.transport == "tcp" and
113      source.port >= 49152 and destination.port >= 49152 and source.ip != "127.0.0.1" and source.ip != "::1"
114   ] by host.id, process.entity_id
115   [process where host.os.type == "windows" and 
116       event.type == "start" and process.parent.name : "services.exe" and
117       not (process.executable : "?:\\Windows\\System32\\msiexec.exe" and process.args : "/V") and
118       not process.executable : (
119                "?:\\Pella Corporation\\OSCToGPAutoService\\OSCToGPAutoSvc.exe",
120                "?:\\Pella Corporation\\Pella Order Management\\GPAutoSvc.exe",
121                "?:\\Pella Corporation\\Pella Order Management\\GPAutoSvc.exe",
122                "?:\\Program Files (x86)\\*.exe",
123                "?:\\Program Files\\*.exe",
124                "?:\\Windows\\ADCR_Agent\\adcrsvc.exe",
125                "?:\\Windows\\AdminArsenal\\PDQ*.exe",
126                "?:\\Windows\\CAInvokerService.exe",
127                "?:\\Windows\\ccmsetup\\ccmsetup.exe",
128                "?:\\Windows\\eset-remote-install-service.exe",
129                "?:\\Windows\\ProPatches\\Scheduler\\STSchedEx.exe",
130                "?:\\Windows\\PSEXESVC.EXE",
131                "?:\\Windows\\RemoteAuditService.exe",
132                "?:\\Windows\\servicing\\TrustedInstaller.exe",
133                "?:\\Windows\\System32\\certsrv.exe",
134                "?:\\Windows\\System32\\sppsvc.exe",
135                "?:\\Windows\\System32\\srmhost.exe",
136                "?:\\Windows\\System32\\svchost.exe",
137                "?:\\Windows\\System32\\taskhostex.exe",
138                "?:\\Windows\\System32\\upfc.exe",
139                "?:\\Windows\\System32\\vds.exe",
140                "?:\\Windows\\System32\\VSSVC.exe",
141                "?:\\Windows\\System32\\wbem\\WmiApSrv.exe",
142                "?:\\Windows\\SysWOW64\\NwxExeSvc\\NwxExeSvc.exe",
143                "?:\\Windows\\Veeam\\Backup\\VeeamDeploymentSvc.exe",
144                "?:\\Windows\\VeeamLogShipper\\VeeamLogShipper.exe",
145                "?:\\Windows\\VeeamVssSupport\\VeeamGuestHelper.exe"
146       )] by host.id, process.parent.entity_id
147'''
148
149
150[[rule.threat]]
151framework = "MITRE ATT&CK"
152[[rule.threat.technique]]
153id = "T1021"
154name = "Remote Services"
155reference = "https://attack.mitre.org/techniques/T1021/"
156
157
158[rule.threat.tactic]
159id = "TA0008"
160name = "Lateral Movement"
161reference = "https://attack.mitre.org/tactics/TA0008/"