Merge branch 'main' into issue-4023

Author: shashank-elastic

.github/workflows/version-code-and-release.yml

@@ -7,6 +7,7 @@ on:
       - 'hunting/**/*.py'
       - '!hunting/**/*.md'
       - '!hunting/index.md'
+      - '!hunting/**/*.toml'
       - 'pyproject.toml'
       - 'Makefile'
       - 'docs/**'

hunting/linux/docs/persistence_via_ssh_configurations_and_keys.md

@@ -37,7 +37,7 @@ SELECT
     g.groupname AS group_owner,
     datetime(f.atime, 'unixepoch') AS file_last_access_time,
     datetime(f.mtime, 'unixepoch') AS file_last_modified_time,
-    datetime(f.ctime, 'unixepoch') AS file_last_status change_time,
+    datetime(f.ctime, 'unixepoch') AS file_last_status_change_time,
     datetime(f.btime, 'unixepoch') AS file_created_time,
     f.size AS size_bytes
 FROM
@@ -51,7 +51,27 @@ WHERE
     OR f.path LIKE "/home/%/.ssh/%"
     OR f.path LIKE "/etc/ssh/%"
     OR f.path LIKE "/etc/ssh/sshd_config.d/%"
-    OR f.path LIKE "/etc/ssh/ssh_config.d/%"
+    OR f.path LIKE "/usr/sbin/.ssh/%"
+    OR f.path LIKE "/bin/.ssh/%"
+    OR f.path LIKE "/usr/games/.ssh/%"
+    OR f.path LIKE "/var/cache/man/.ssh/%"
+    OR f.path LIKE "/var/mail/.ssh/%"
+    OR f.path LIKE "/var/spool/news/.ssh/%"
+    OR f.path LIKE "/var/spool/lpd/.ssh/%"
+    OR f.path LIKE "/var/backups/.ssh/%"
+    OR f.path LIKE "/var/list/.ssh/%"
+    OR f.path LIKE "/run/ircd/.ssh/%"
+    OR f.path LIKE "/var/lib/gnats/.ssh/%"
+    OR f.path LIKE "/nonexistent/.ssh/%"
+    OR f.path LIKE "/run/systemd/.ssh/%"
+    OR f.path LIKE "/var/cache/pollinate/.ssh/%"
+    OR f.path LIKE "/run/sshd/.ssh/%"
+    OR f.path LIKE "/home/syslog/.ssh/%"
+    OR f.path LIKE "/run/uuidd/.ssh/%"
+    OR f.path LIKE "/var/lib/tpm/.ssh/%"
+    OR f.path LIKE "/var/lib/landscape/.ssh/%"
+    OR f.path LIKE "/var/lib/usbmux/.ssh/%"
+    OR f.path LIKE "/var/snap/lxd/common/lxd/.ssh/%";
 ```
 
 ```sql

hunting/linux/queries/persistence_via_ssh_configurations_and_keys.toml

@@ -37,7 +37,7 @@ SELECT
     g.groupname AS group_owner,
     datetime(f.atime, 'unixepoch') AS file_last_access_time,
     datetime(f.mtime, 'unixepoch') AS file_last_modified_time,
-    datetime(f.ctime, 'unixepoch') AS file_last_status change_time,
+    datetime(f.ctime, 'unixepoch') AS file_last_status_change_time,
     datetime(f.btime, 'unixepoch') AS file_created_time,
     f.size AS size_bytes
 FROM
@@ -51,7 +51,27 @@ WHERE
     OR f.path LIKE "/home/%/.ssh/%"
     OR f.path LIKE "/etc/ssh/%"
     OR f.path LIKE "/etc/ssh/sshd_config.d/%"
-    OR f.path LIKE "/etc/ssh/ssh_config.d/%"
+    OR f.path LIKE "/usr/sbin/.ssh/%"
+    OR f.path LIKE "/bin/.ssh/%"
+    OR f.path LIKE "/usr/games/.ssh/%"
+    OR f.path LIKE "/var/cache/man/.ssh/%"
+    OR f.path LIKE "/var/mail/.ssh/%"
+    OR f.path LIKE "/var/spool/news/.ssh/%"
+    OR f.path LIKE "/var/spool/lpd/.ssh/%"
+    OR f.path LIKE "/var/backups/.ssh/%"
+    OR f.path LIKE "/var/list/.ssh/%"
+    OR f.path LIKE "/run/ircd/.ssh/%"
+    OR f.path LIKE "/var/lib/gnats/.ssh/%"
+    OR f.path LIKE "/nonexistent/.ssh/%"
+    OR f.path LIKE "/run/systemd/.ssh/%"
+    OR f.path LIKE "/var/cache/pollinate/.ssh/%"
+    OR f.path LIKE "/run/sshd/.ssh/%"
+    OR f.path LIKE "/home/syslog/.ssh/%"
+    OR f.path LIKE "/run/uuidd/.ssh/%"
+    OR f.path LIKE "/var/lib/tpm/.ssh/%"
+    OR f.path LIKE "/var/lib/landscape/.ssh/%"
+    OR f.path LIKE "/var/lib/usbmux/.ssh/%"
+    OR f.path LIKE "/var/snap/lxd/common/lxd/.ssh/%";
 ''',
 '''
 from logs-endpoint.events.process-*

rules/integrations/azure/defense_evasion_azure_blob_permissions_modified.toml

@@ -2,7 +2,7 @@
 creation_date = "2021/09/22"
 integration = ["azure"]
 maturity = "production"
-updated_date = "2024/05/21"
+updated_date = "2025/01/11"
 
 [rule]
 author = ["Austin Songer"]
@@ -32,8 +32,7 @@ tags = [
     "Domain: Cloud",
     "Data Source: Azure",
     "Use Case: Identity and Access Audit",
-    "Tactic: Defense Evasion",
-    "Data Source: Elastic Defend",
+    "Tactic: Defense Evasion"
 ]
 timestamp_override = "event.ingested"
 type = "query"

rules/linux/defense_evasion_prctl_process_name_tampering.toml

@@ -0,0 +1,85 @@
+[metadata]
+creation_date = "2025/01/09"
+integration = ["auditd_manager"]
+maturity = "production"
+updated_date = "2025/01/09"
+
+[rule]
+author = ["Elastic"]
+description = """
+This rule leverages Auditd data to detect the use of the `prctl` syscall to potentially hide a process
+by changing its name. The `prctl` syscall is used to control various process attributes. Attackers can use
+this syscall to change the name of a process to a hidden directory or file, making it harder to detect. The query
+looks for the `prctl` syscall with the `PR_SET_NAME` argument set to `f` (PR_SET_NAME is used to set the name of a process).
+"""
+from = "now-9m"
+index = ["logs-auditd_manager.auditd-*", "auditbeat-*"]
+language = "eql"
+license = "Elastic License v2"
+name = "Potential Process Name Stomping with Prctl"
+references = [
+    "https://haxrob.net/process-name-stomping/",
+    "https://haxrob.net/hiding-in-plain-sight-part-2/",
+    "https://www.elastic.co/security-labs/linux-detection-engineering-with-auditd",
+]
+risk_score = 47
+rule_id = "fef62ecf-0260-4b71-848b-a8624b304828"
+setup = """## Setup
+
+This rule requires data coming in from Auditd Manager.
+
+### Auditd Manager Integration Setup
+The Auditd Manager Integration receives audit events from the Linux Audit Framework which is a part of the Linux kernel.
+Auditd Manager provides a user-friendly interface and automation capabilities for configuring and monitoring system auditing through the auditd daemon. With `auditd_manager`, administrators can easily define audit rules, track system events, and generate comprehensive audit reports, improving overall security and compliance in the system.
+
+#### The following steps should be executed in order to add the Elastic Agent System integration "auditd_manager" on a Linux System:
+- Go to the Kibana home page and click “Add integrations”.
+- In the query bar, search for “Auditd Manager” and select the integration to see more details about it.
+- Click “Add Auditd Manager”.
+- Configure the integration name and optionally add a description.
+- Review optional and advanced settings accordingly.
+- Add the newly installed “auditd manager” to an existing or a new agent policy, and deploy the agent on a Linux system from which auditd log files are desirable.
+- Click “Save and Continue”.
+- For more details on the integration refer to the [helper guide](https://docs.elastic.co/integrations/auditd_manager).
+
+#### Rule Specific Setup Note
+Auditd Manager subscribes to the kernel and receives events as they occur without any additional configuration.
+However, if more advanced configuration is required to detect specific behavior, audit rules can be added to the integration in either the "audit rules" configuration box or the "auditd rule files" box by specifying a file to read the audit rules from.
+- For this detection rule the following additional audit rules are required to be added to the integration:
+  -- "-a exit,always -F arch=b64 -S prctl -k prctl_detection"
+"""
+severity = "medium"
+tags = [
+    "Data Source: Auditd Manager",
+    "Domain: Endpoint",
+    "OS: Linux",
+    "Use Case: Threat Detection",
+    "Tactic: Defense Evasion",
+]
+timestamp_override = "event.ingested"
+type = "eql"
+query = '''
+process where host.os.type == "linux" and auditd.data.syscall == "prctl" and auditd.data.a0 == "f" and
+process.executable like (
+  "/boot/*", "/dev/shm/*", "/etc/cron.*/*", "/etc/init.d/*", "/var/run/*", "/etc/update-motd.d/*",
+  "/tmp/*", "/var/log/*", "/var/tmp/*", "/home/*", "/run/shm/*", "/run/*", "./*"
+)
+'''
+
+[[rule.threat]]
+framework = "MITRE ATT&CK"
+
+[[rule.threat.technique]]
+id = "T1036"
+name = "Masquerading"
+reference = "https://attack.mitre.org/techniques/T1036/"
+
+[[rule.threat.technique.subtechnique]]
+id = "T1036.005"
+name = "Match Legitimate Name or Location"
+reference = "https://attack.mitre.org/techniques/T1036/005/"
+
+[rule.threat.tactic]
+id = "TA0005"
+name = "Defense Evasion"
+reference = "https://attack.mitre.org/tactics/TA0005/"

rules/windows/defense_evasion_audit_policy_disabled_winlog.toml

@@ -0,0 +1,127 @@
+[metadata]
+creation_date = "2025/01/14"
+integration = ["windows", "system"]
+maturity = "production"
+updated_date = "2025/01/14"
+min_stack_version = "8.14.0"
+min_stack_comments = "Breaking change at 8.14.0 for the Windows Integration."
+
+[rule]
+author = ["Elastic"]
+description = """
+Identifies attempts to disable auditing for some security sensitive audit policy sub-categories. This is often done by
+attackers in an attempt to evade detection and forensics on a system.
+"""
+from = "now-9m"
+index = [
+    "winlogbeat-*",
+    "logs-windows.forwarded*",
+    "logs-system.security-*"
+]
+language = "kuery"
+license = "Elastic License v2"
+name = "Sensitive Audit Policy Sub-Category Disabled"
+note = """## Triage and analysis
+
+### Investigating Sensitive Audit Policy Sub-Category Disabled
+
+Windows event logs are a fundamental data source for security monitoring, forensics, and incident response. Adversaries can tamper, clear, and delete this data to break SIEM detections, cover their tracks, and slow down incident response.
+
+This rule looks for attempts to disable security-sensitive audit policies.
+
+#### Possible investigation steps
+
+- 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.
+- Identify the user account that performed the action and whether it should perform this kind of action.
+- Contact the account owner and confirm whether they are aware of this activity.
+- Investigate other alerts associated with the user/host during the past 48 hours.
+  - Verify if any other anti-forensics behaviors were observed.
+- Investigate the event logs prior to the action for suspicious behaviors that an attacker may be trying to cover up.
+
+### False positive analysis
+
+- This activity is unlikely to happen legitimately. Benign true positives (B-TPs) can be added as exceptions if necessary.
+
+### Response and remediation
+
+- Initiate the incident response process based on the outcome of the triage.
+- Isolate the involved host to prevent further post-compromise behavior.
+- Re-enable affected logging components, services, and security monitoring.
+- 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.
+- Run a full antimalware scan. This may reveal additional artifacts left in the system, persistence mechanisms, and malware components.
+- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.
+- 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).
+"""
+references = [
+    "https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-10/security/threat-protection/auditing/event-4719",
+    "https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-gpac/77878370-0712-47cd-997d-b07053429f6d",
+]
+risk_score = 47
+rule_id = "0ef5d3eb-67ef-43ab-93b7-305cfa5a21f6"
+setup = """## Setup
+
+The 'Audit Audit Policy Change' logging policy must be configured for (Success, Failure).
+Steps to implement the logging policy with Advanced Audit Configuration:
+
+```
+Computer Configuration >
+Policies >
+Windows Settings >
+Security Settings >
+Advanced Audit Policies Configuration >
+Audit Policies >
+Policy Change >
+Audit Audit Policy Change (Success,Failure)
+```
+"""
+severity = "medium"
+tags = [
+    "Domain: Endpoint",
+    "OS: Windows",
+    "Use Case: Threat Detection",
+    "Tactic: Defense Evasion",
+    "Resources: Investigation Guide",
+    "Data Source: System",
+]
+timestamp_override = "event.ingested"
+type = "query"
+
+query = '''
+event.action : "changed-audit-config" and event.code : "4719" and host.os.type : "windows" and
+ winlog.event_data.AuditPolicyChangesDescription : "Success removed" and
+ winlog.event_data.SubCategory : ("Logon" or "Audit Policy Change" or "Process Creation" or "Audit Other System Events" or "Audit Security Group Management" or "Audit User Account Management")
+'''
+
+
+[[rule.threat]]
+framework = "MITRE ATT&CK"
+[[rule.threat.technique]]
+id = "T1070"
+name = "Indicator Removal"
+reference = "https://attack.mitre.org/techniques/T1070/"
+[[rule.threat.technique.subtechnique]]
+id = "T1070.001"
+name = "Clear Windows Event Logs"
+reference = "https://attack.mitre.org/techniques/T1070/001/"
+
+
+[[rule.threat.technique]]
+id = "T1562"
+name = "Impair Defenses"
+reference = "https://attack.mitre.org/techniques/T1562/"
+[[rule.threat.technique.subtechnique]]
+id = "T1562.002"
+name = "Disable Windows Event Logging"
+reference = "https://attack.mitre.org/techniques/T1562/002/"
+
+[[rule.threat.technique.subtechnique]]
+id = "T1562.006"
+name = "Indicator Blocking"
+reference = "https://attack.mitre.org/techniques/T1562/006/"
+
+
+
+[rule.threat.tactic]
+id = "TA0005"
+name = "Defense Evasion"
+reference = "https://attack.mitre.org/tactics/TA0005/"

rules_building_block/collection_common_compressed_archived_file.toml

@@ -3,21 +3,20 @@ bypass_bbr_timing = true
 creation_date = "2023/10/11"
 integration = "endpoint"
 maturity = "production"
-updated_date = "2024/05/21"
+updated_date = "2025/01/09"
 
 [rule]
 author = ["Elastic"]
 building_block_type = "default"
 description = """
-Detects files being compressed or archived into common formats. This is a common technique used to obfuscate files to
-evade detection or to staging data for exfiltration.
+Detects files being compressed or archived into common formats by unsigned processes. This is a common technique used to
+obfuscate files to evade detection or to staging data for exfiltration.
 """
 from = "now-9m"
 index = ["logs-endpoint.events.file-*"]
 language = "eql"
 license = "Elastic License v2"
-max_signals = 1000
-name = "File Compressed or Archived into Common Format"
+name = "File Compressed or Archived into Common Format by Unsigned Process"
 references = ["https://en.wikipedia.org/wiki/List_of_file_signatures"]
 risk_score = 21
 rule_id = "79124edf-30a8-4d48-95c4-11522cad94b1"
@@ -34,7 +33,8 @@ timestamp_override = "event.ingested"
 type = "eql"
 
 query = '''
-file where host.os.type == "windows" and event.type in ("creation", "change") and process.executable != null and not user.id : ("S-1-5-18", "S-1-5-17") and
+file where host.os.type == "windows" and event.type in ("creation", "change") and
+ process.executable != null and process.code_signature.trusted != true and
  file.Ext.header_bytes : (
                           /* compression formats */
                           "1F9D*",             /* tar zip, tar.z (Lempel-Ziv-Welch algorithm) */
@@ -70,44 +70,6 @@ file where host.os.type == "windows" and event.type in ("creation", "change") an
                           "78617221*",         /* xar */
                           "4F4152*",           /* oar */
                           "49536328*"          /* cab archive */
- ) and
- not (
-   (
-     process.name : "firefox.exe" and
-     process.code_signature.subject_name : "Mozilla Corporation" and process.code_signature.trusted == true
-   ) or
-   (
-     process.name : "wazuh-agent.exe" and
-     process.code_signature.subject_name : "Wazuh, Inc" and process.code_signature.trusted == true and
-     file.name : ("ossec-*.log.gz", "tmp-entry.gz", "tmp-entry", "last-entry.gz")
-   ) or
-   (
-     process.name : ("excel.exe", "winword.exe", "powerpnt.exe") and
-     process.code_signature.subject_name : "Microsoft Corporation" and process.code_signature.trusted == true
-   ) or
-   (
-     process.name : "OneDrive.exe" and
-     process.code_signature.subject_name : "Microsoft Corporation" and process.code_signature.trusted == true and
-     (
-      file.extension : ("xlsx", "docx", "pptx", "xlsm") or
-      file.path : "?:\\Users\\*\\AppData\\Local\\Microsoft\\OneDrive\\logs\\*"
-     )
-   ) or
-   (
-     process.name : "Dropbox.exe" and
-     process.code_signature.subject_name : "Dropbox, Inc" and process.code_signature.trusted == true and
-     file.name : "store.bin"
-   ) or
-   (
-     process.name : "DellSupportAssistRemedationService.exe" and
-     process.code_signature.subject_name : "Dell Inc" and process.code_signature.trusted == true and
-     file.extension : "manifest"
-   ) or
-   (
-     process.name : "w3wp.exe" and
-     process.code_signature.subject_name : "Microsoft Windows" and process.code_signature.trusted == true and
-     file.path : "?:\\inetpub\\temp\\IIS Temporary Compressed Files\\*"
-   )
  )
 '''