Deleting Backup Catalogs with Wbadmin

  1[metadata]
  2creation_date = "2020/02/18"
  3integration = ["endpoint", "windows", "system"]
  4maturity = "production"
  5updated_date = "2024/05/21"
  6
  7[rule]
  8author = ["Elastic"]
  9description = """
 10Identifies use of the wbadmin.exe to delete the backup catalog. Ransomware and other malware may do this to prevent
 11system recovery.
 12"""
 13from = "now-9m"
 14index = [
 15    "winlogbeat-*",
 16    "logs-endpoint.events.process-*",
 17    "logs-windows.*",
 18    "endgame-*",
 19    "logs-system.security*",
 20]
 21language = "eql"
 22license = "Elastic License v2"
 23name = "Deleting Backup Catalogs with Wbadmin"
 24note = """## Triage and analysis
 25
 26### Investigating Deleting Backup Catalogs with Wbadmin
 27
 28Windows Server Backup stores the details about your backups (what volumes are backed up and where the backups are located) in a file called a backup catalog, which ransomware victims can use to recover corrupted backup files. Deleting these files is a common step in threat actor playbooks.
 29
 30This rule identifies the deletion of the backup catalog using the `wbadmin.exe` utility.
 31
 32#### Possible investigation steps
 33
 34- 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.
 35- Identify the user account that performed the action and whether it should perform this kind of action.
 36- Contact the account owner and confirm whether they are aware of this activity.
 37- Investigate other alerts associated with the user/host during the past 48 hours.
 38- Assess whether this behavior is prevalent in the environment by looking for similar occurrences across hosts.
 39- Check if any files on the host machine have been encrypted.
 40
 41### False positive analysis
 42
 43- Administrators can use this command to delete corrupted catalogs, but overall the activity is unlikely to be legitimate.
 44
 45### Related rules
 46
 47- Third-party Backup Files Deleted via Unexpected Process - 11ea6bec-ebde-4d71-a8e9-784948f8e3e9
 48- Volume Shadow Copy Deleted or Resized via VssAdmin - b5ea4bfe-a1b2-421f-9d47-22a75a6f2921
 49- Volume Shadow Copy Deletion via PowerShell - d99a037b-c8e2-47a5-97b9-170d076827c4
 50- Volume Shadow Copy Deletion via WMIC - dc9c1f74-dac3-48e3-b47f-eb79db358f57
 51
 52### Response and remediation
 53
 54- Initiate the incident response process based on the outcome of the triage.
 55- Consider isolating the involved host to prevent destructive behavior, which is commonly associated with this activity.
 56- 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.
 57- If any other destructive action was identified on the host, it is recommended to prioritize the investigation and look for ransomware preparation and execution activities.
 58- If any backups were affected:
 59  - Perform data recovery locally or restore the backups from replicated copies (cloud, other servers, etc.).
 60- Determine the initial vector abused by the attacker and take action to prevent reinfection through the same vector.
 61- 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).
 62"""
 63risk_score = 21
 64rule_id = "581add16-df76-42bb-af8e-c979bfb39a59"
 65setup = """## Setup
 66
 67If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2,
 68events will not define `event.ingested` and default fallback for EQL rules was not added until version 8.2.
 69Hence for this rule to work effectively, users will need to add a custom ingest pipeline to populate
 70`event.ingested` to @timestamp.
 71For more details on adding a custom ingest pipeline refer - https://www.elastic.co/guide/en/fleet/current/data-streams-pipeline-tutorial.html
 72"""
 73severity = "low"
 74tags = [
 75    "Domain: Endpoint",
 76    "OS: Windows",
 77    "Use Case: Threat Detection",
 78    "Tactic: Impact",
 79    "Resources: Investigation Guide",
 80    "Data Source: Elastic Endgame",
 81    "Data Source: Elastic Defend",
 82]
 83timestamp_override = "event.ingested"
 84type = "eql"
 85
 86query = '''
 87process where host.os.type == "windows" and event.type == "start" and
 88  (process.name : "wbadmin.exe" or ?process.pe.original_file_name == "WBADMIN.EXE") and
 89  process.args : "catalog" and process.args : "delete"
 90'''
 91
 92
 93[[rule.threat]]
 94framework = "MITRE ATT&CK"
 95[[rule.threat.technique]]
 96id = "T1485"
 97name = "Data Destruction"
 98reference = "https://attack.mitre.org/techniques/T1485/"
 99
100[[rule.threat.technique]]
101id = "T1490"
102name = "Inhibit System Recovery"
103reference = "https://attack.mitre.org/techniques/T1490/"
104
105
106[rule.threat.tactic]
107id = "TA0040"
108name = "Impact"
109reference = "https://attack.mitre.org/tactics/TA0040/"