Startup or Run Key Registry Modification

  1[metadata]
  2creation_date = "2020/11/18"
  3integration = ["endpoint"]
  4maturity = "production"
  5updated_date = "2024/05/21"
  6
  7[transform]
  8[[transform.osquery]]
  9label = "Osquery - Retrieve DNS Cache"
 10query = "SELECT * FROM dns_cache"
 11
 12[[transform.osquery]]
 13label = "Osquery - Retrieve All Services"
 14query = "SELECT description, display_name, name, path, pid, service_type, start_type, status, user_account FROM services"
 15
 16[[transform.osquery]]
 17label = "Osquery - Retrieve Services Running on User Accounts"
 18query = """
 19SELECT description, display_name, name, path, pid, service_type, start_type, status, user_account FROM services WHERE
 20NOT (user_account LIKE '%LocalSystem' OR user_account LIKE '%LocalService' OR user_account LIKE '%NetworkService' OR
 21user_account == null)
 22"""
 23
 24[[transform.osquery]]
 25label = "Osquery - Retrieve Service Unsigned Executables with Virustotal Link"
 26query = """
 27SELECT concat('https://www.virustotal.com/gui/file/', sha1) AS VtLink, name, description, start_type, status, pid,
 28services.path FROM services JOIN authenticode ON services.path = authenticode.path OR services.module_path =
 29authenticode.path JOIN hash ON services.path = hash.path WHERE authenticode.result != 'trusted'
 30"""
 31
 32
 33[rule]
 34author = ["Elastic"]
 35description = """
 36Identifies run key or startup key registry modifications. In order to survive reboots and other system interrupts,
 37attackers will modify run keys within the registry or leverage startup folder items as a form of persistence.
 38"""
 39from = "now-9m"
 40index = ["logs-endpoint.events.registry-*"]
 41language = "eql"
 42license = "Elastic License v2"
 43name = "Startup or Run Key Registry Modification"
 44note = """## Triage and analysis
 45
 46### Investigating Startup or Run Key Registry Modification
 47
 48Adversaries may achieve persistence by referencing a program with a registry run key. Adding an entry to the run keys in the registry will cause the program referenced to be executed when a user logs in. These programs will executed under the context of the user and will have the account's permissions. This rule looks for this behavior by monitoring a range of registry run keys.
 49
 50> **Note**:
 51> 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.
 52
 53#### Possible investigation steps
 54
 55- 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.
 56- Investigate other alerts associated with the user/host during the past 48 hours.
 57- Validate if the activity is not related to planned patches, updates, network administrator activity, or legitimate software installations.
 58- Assess whether this behavior is prevalent in the environment by looking for similar occurrences across hosts.
 59- Examine the host for derived artifacts that indicate suspicious activities:
 60  - Analyze the process executable using a private sandboxed analysis system.
 61  - Observe and collect information about the following activities in both the sandbox and the alert subject host:
 62    - Attempts to contact external domains and addresses.
 63      - Use the Elastic Defend network events to determine domains and addresses contacted by the subject process by filtering by the process' `process.entity_id`.
 64      - Examine the DNS cache for suspicious or anomalous entries.
 65        - $osquery_0
 66    - Use the Elastic Defend registry events to examine registry keys accessed, modified, or created by the related processes in the process tree.
 67    - Examine the host services for suspicious or anomalous entries.
 68      - $osquery_1
 69      - $osquery_2
 70      - $osquery_3
 71  - 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.
 72- Investigate potentially compromised accounts. Analysts can do this by searching for login events (for example, 4624) to the target host after the registry modification.
 73
 74
 75### False positive analysis
 76
 77- There is a high possibility of benign legitimate programs being added to registry run keys. This activity could be based on new software installations, patches, or any kind of network administrator related activity. Before undertaking further investigation, verify that this activity is not benign.
 78
 79### Related rules
 80
 81- Suspicious Startup Shell Folder Modification - c8b150f0-0164-475b-a75e-74b47800a9ff
 82- Persistent Scripts in the Startup Directory - f7c4dc5a-a58d-491d-9f14-9b66507121c0
 83- Startup Folder Persistence via Unsigned Process - 2fba96c0-ade5-4bce-b92f-a5df2509da3f
 84- Startup Persistence by a Suspicious Process - 440e2db4-bc7f-4c96-a068-65b78da59bde
 85
 86### Response and remediation
 87
 88- Initiate the incident response process based on the outcome of the triage.
 89- Isolate the involved host to prevent further post-compromise behavior.
 90- If the triage identified malware, search the environment for additional compromised hosts.
 91  - Implement temporary network rules, procedures, and segmentation to contain the malware.
 92  - Stop suspicious processes.
 93  - Immediately block the identified indicators of compromise (IoCs).
 94  - Inspect the affected systems for additional malware backdoors like reverse shells, reverse proxies, or droppers that attackers could use to reinfect the system.
 95- Remove and block malicious artifacts identified during triage.
 96- 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.
 97- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.
 98- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.
 99- 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).
100"""
101risk_score = 21
102rule_id = "97fc44d3-8dae-4019-ae83-298c3015600f"
103severity = "low"
104tags = [
105    "Domain: Endpoint",
106    "OS: Windows",
107    "Use Case: Threat Detection",
108    "Tactic: Persistence",
109    "Resources: Investigation Guide",
110    "Data Source: Elastic Endgame",
111    "Data Source: Elastic Defend",
112]
113timeline_id = "3e47ef71-ebfc-4520-975c-cb27fc090799"
114timeline_title = "Comprehensive Registry Timeline"
115timestamp_override = "event.ingested"
116type = "eql"
117
118query = '''
119registry where host.os.type == "windows" and registry.data.strings != null and
120 registry.path : (
121     /* Machine Hive */
122     "HKLM\\Software\\Microsoft\\Windows\\CurrentVersion\\Run\\*",
123     "HKLM\\Software\\Microsoft\\Windows\\CurrentVersion\\RunOnce\\*",
124     "HKLM\\Software\\Microsoft\\Windows\\CurrentVersion\\RunOnceEx\\*",
125     "HKLM\\Software\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer\\Run\\*",
126     "HKLM\\Software\\Microsoft\\Windows NT\\CurrentVersion\\Winlogon\\Shell\\*",
127     /* Users Hive */
128     "HKEY_USERS\\*\\Software\\Microsoft\\Windows\\CurrentVersion\\Run\\*",
129     "HKEY_USERS\\*\\Software\\Microsoft\\Windows\\CurrentVersion\\RunOnce\\*",
130     "HKEY_USERS\\*\\Software\\Microsoft\\Windows\\CurrentVersion\\RunOnceEx\\*",
131     "HKEY_USERS\\*\\Software\\Microsoft\\Windows\\CurrentVersion\\Policies\\Explorer\\Run\\*",
132     "HKEY_USERS\\*\\Software\\Microsoft\\Windows NT\\CurrentVersion\\Winlogon\\Shell\\*"
133     ) and
134  /* add common legitimate changes without being too restrictive as this is one of the most abused AESPs */
135  not registry.data.strings : "ctfmon.exe /n" and
136  not (registry.value : "Application Restart #*" and process.name : "csrss.exe") and
137  not user.id : ("S-1-5-18", "S-1-5-19", "S-1-5-20") and
138  not registry.data.strings : ("?:\\Program Files\\*.exe", "?:\\Program Files (x86)\\*.exe") and
139  not process.executable : ("?:\\Windows\\System32\\msiexec.exe", "?:\\Windows\\SysWOW64\\msiexec.exe") and
140  not (
141    /* Logitech G Hub */
142    (
143      process.code_signature.trusted == true and process.code_signature.subject_name == "Logitech Inc" and
144      (
145        process.name : "lghub_agent.exe" and registry.data.strings : (
146          "\"?:\\Program Files\\LGHUB\\lghub.exe\" --background",
147          "\"?:\\Program Files\\LGHUB\\system_tray\\lghub_system_tray.exe\" --minimized"
148        )
149      ) or
150      (
151        process.name : "LogiBolt.exe" and registry.data.strings : (
152          "?:\\Program Files\\Logi\\LogiBolt\\LogiBolt.exe --startup",
153          "?:\\Users\\*\\AppData\\Local\\Logi\\LogiBolt\\LogiBolt.exe --startup"
154        )
155      )
156    ) or
157
158    /* Google Drive File Stream, Chrome, and Google Update */
159    (
160      process.code_signature.trusted == true and process.code_signature.subject_name == "Google LLC" and
161      (
162        process.name : "GoogleDriveFS.exe" and registry.data.strings : (
163        "\"?:\\Program Files\\Google\\Drive File Stream\\*\\GoogleDriveFS.exe\" --startup_mode"
164        ) or
165
166        process.name : "chrome.exe" and registry.data.strings : (
167          "\"?:\\Program Files\\Google\\Chrome\\Application\\chrome.exe\" --no-startup-window /prefetch:5",
168          "\"?:\\Program Files (x86)\\Google\\Chrome\\Application\\chrome.exe\" --no-startup-window /prefetch:5"
169        ) or
170
171        process.name : "GoogleUpdate.exe" and registry.data.strings : (
172          "\"?:\\Users\\*\\AppData\\Local\\Google\\Update\\*\\GoogleUpdateCore.exe\""
173        )
174      )
175    ) or
176
177    /* MS Programs */
178    (
179      process.code_signature.trusted == true and process.code_signature.subject_name in ("Microsoft Windows", "Microsoft Corporation") and
180      (
181        process.name : "msedge.exe" and registry.data.strings : (
182          "\"?:\\Program Files (x86)\\Microsoft\\Edge\\Application\\msedge.exe\" --no-startup-window --win-session-start /prefetch:5",
183          "\"C:\\Program Files (x86)\\Microsoft\\Edge\\Application\\msedge.exe\" --win-session-start",
184          "\"C:\\Program Files (x86)\\Microsoft\\Edge\\Application\\msedge.exe\" --no-startup-window --win-session-start"
185        ) or
186
187        process.name : ("Update.exe", "Teams.exe") and registry.data.strings : (
188          "?:\\Users\\*\\AppData\\Local\\Microsoft\\Teams\\Update.exe --processStart \"Teams.exe\" --process-start-args \"--system-initiated\"",
189          "?:\\ProgramData\\*\\Microsoft\\Teams\\Update.exe --processStart \"Teams.exe\" --process-start-args \"--system-initiated\""
190        ) or
191
192        process.name : "OneDriveStandaloneUpdater.exe" and registry.data.strings : (
193          "?:\\Users\\*\\AppData\\Local\\Microsoft\\OneDrive\\*\\Microsoft.SharePoint.exe"
194        ) or
195
196        process.name : "OneDriveSetup.exe" and
197          registry.data.strings : (
198            "?:\\Windows\\system32\\cmd.exe /q /c * \"?:\\Users\\*\\AppData\\Local\\Microsoft\\OneDrive\\*\"",
199            "?:\\Program Files (x86)\\Microsoft OneDrive\\OneDrive.exe /background*",
200            "\"?:\\Program Files (x86)\\Microsoft OneDrive\\OneDrive.exe\" /background*",
201            "?:\\Program Files\\Microsoft OneDrive\\OneDrive.exe /background *",
202            "?:\\Users\\*\\AppData\\Local\\Microsoft\\OneDrive\\??.???.????.????\\Microsoft.SharePoint.exe"
203          ) or
204        
205        process.name : "OneDrive.exe" and registry.data.strings : (
206          "\"?:\\Program Files\\Microsoft OneDrive\\OneDrive.exe\" /background",
207          "\"?:\\Program Files (x86)\\Microsoft OneDrive\\OneDrive.exe\" /background",
208          "\"?:\\Users\\*\\AppData\\Local\\Microsoft\\OneDrive\\OneDrive.exe\" /background"
209        ) or
210        
211        process.name : "Microsoft.SharePoint.exe" and registry.data.strings : (
212          "?:\\Users\\*\\AppData\\Local\\Microsoft\\OneDrive\\??.???.????.????\\Microsoft.SharePoint.exe"
213        ) or
214        
215        process.name : "MicrosoftEdgeUpdate.exe" and registry.data.strings : (
216          "\"?:\\Users\\Expedient\\AppData\\Local\\Microsoft\\EdgeUpdate\\*\\MicrosoftEdgeUpdateCore.exe\""
217        ) or
218        
219        process.executable : "?:\\Program Files (x86)\\Microsoft\\EdgeWebView\\Application\\*\\Installer\\setup.exe" and
220        registry.data.strings : (
221          "\"?:\\Program Files (x86)\\Microsoft\\EdgeWebView\\Application\\*\\Installer\\setup.exe\" --msedgewebview --delete-old-versions --system-level --verbose-logging --on-logon"
222        )
223      )
224    ) or
225
226    /* Slack */
227    (
228      process.code_signature.trusted == true and process.code_signature.subject_name in (
229       "Slack Technologies, Inc.", "Slack Technologies, LLC"
230      ) and process.name : "slack.exe" and registry.data.strings : (
231        "\"?:\\Users\\*\\AppData\\Local\\slack\\slack.exe\" --process-start-args --startup",
232        "\"?:\\ProgramData\\*\\slack\\slack.exe\" --process-start-args --startup",
233        "\"?:\\Program Files\\Slack\\slack.exe\" --process-start-args --startup"
234      )
235    ) or
236
237    /* Cisco */
238    (
239      process.code_signature.trusted == true and process.code_signature.subject_name in ("Cisco WebEx LLC", "Cisco Systems, Inc.") and
240      (
241        process.name : "WebexHost.exe" and registry.data.strings : (
242          "\"?:\\Users\\*\\AppData\\Local\\WebEx\\WebexHost.exe\" /daemon /runFrom=autorun"
243        )
244      ) or
245      (
246        process.name : "CiscoJabber.exe" and registry.data.strings : (
247          "\"?:\\Program Files (x86)\\Cisco Systems\\Cisco Jabber\\CiscoJabber.exe\" /min"
248        )
249      )
250    ) or
251
252    /* Loom */
253    (
254      process.code_signature.trusted == true and process.code_signature.subject_name == "Loom, Inc." and
255      process.name : "Loom.exe" and registry.data.strings : (
256        "?:\\Users\\*\\AppData\\Local\\Programs\\Loom\\Loom.exe --process-start-args \"--loomHidden\""
257      )
258    ) or
259
260    /* Adobe */
261    (
262      process.code_signature.trusted == true and process.code_signature.subject_name == "Adobe Inc." and
263      process.name : ("Acrobat.exe", "FlashUtil32_*_Plugin.exe") and registry.data.strings : (
264        "\"?:\\Program Files\\Adobe\\Acrobat DC\\Acrobat\\AdobeCollabSync.exe\"",
265        "\"?:\\Program Files (x86)\\Adobe\\Acrobat DC\\Acrobat\\AdobeCollabSync.exe\"",
266        "?:\\WINDOWS\\SysWOW64\\Macromed\\Flash\\FlashUtil32_*_Plugin.exe -update plugin"
267      )
268    ) or
269
270    /* CCleaner */
271    (
272      process.code_signature.trusted == true and process.code_signature.subject_name == "PIRIFORM SOFTWARE LIMITED" and
273      process.name : ("CCleanerBrowser.exe", "CCleaner64.exe") and registry.data.strings : (
274        "\"C:\\Program Files (x86)\\CCleaner Browser\\Application\\CCleanerBrowser.exe\" --check-run=src=logon --auto-launch-at-startup --profile-directory=\"Default\"",
275        "\"C:\\Program Files\\CCleaner\\CCleaner64.exe\" /MONITOR"
276      )
277    ) or
278
279    /* Opera */
280    (
281      process.code_signature.trusted == true and process.code_signature.subject_name == "Opera Norway AS" and
282      process.name : "opera.exe" and registry.data.strings : (
283        "?:\\Users\\*\\AppData\\Local\\Programs\\Opera\\launcher.exe",
284        "?:\\Users\\*\\AppData\\Local\\Programs\\Opera GX\\launcher.exe"
285      )
286    ) or
287
288    /* Avast */
289    (
290      process.code_signature.trusted == true and process.code_signature.subject_name == "Avast Software s.r.o." and
291      process.name : "AvastBrowser.exe" and registry.data.strings : (
292        "\"?:\\Users\\*\\AppData\\Local\\AVAST Software\\Browser\\Application\\AvastBrowser.exe\" --check-run=src=logon --auto-launch-at-startup*",
293        "\"?:\\Program Files (x86)\\AVAST Software\\Browser\\Application\\AvastBrowser.exe\" --check-run=src=logon --auto-launch-at-startup*",
294        ""
295      )
296    ) or
297
298    /* Grammarly */
299    (
300      process.code_signature.trusted == true and process.code_signature.subject_name == "Grammarly, Inc." and
301      process.name : "GrammarlyInstaller.exe" and registry.data.strings : (
302        "?:\\Users\\*\\AppData\\Local\\Grammarly\\DesktopIntegrations\\Grammarly.Desktop.exe"
303      )
304    )
305  )
306'''
307
308
309[[rule.threat]]
310framework = "MITRE ATT&CK"
311[[rule.threat.technique]]
312id = "T1547"
313name = "Boot or Logon Autostart Execution"
314reference = "https://attack.mitre.org/techniques/T1547/"
315[[rule.threat.technique.subtechnique]]
316id = "T1547.001"
317name = "Registry Run Keys / Startup Folder"
318reference = "https://attack.mitre.org/techniques/T1547/001/"
319
320
321
322[rule.threat.tactic]
323id = "TA0003"
324name = "Persistence"
325reference = "https://attack.mitre.org/tactics/TA0003/"