[Detection Rules] Adding Documents for v8.18.5 Pre-Built Detection Rules

docs/detections/prebuilt-rules/downloadable-packages/8-18-5/prebuilt-rule-8-18-5-backup-deletion-with-wbadmin.asciidoc

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+[[prebuilt-rule-8-18-5-backup-deletion-with-wbadmin]]
+=== Backup Deletion with Wbadmin
+
+Detects use of wbadmin.exe to delete backup catalogs, system state backups, or other backup data. Ransomware and other malware may do this to prevent system recovery.
+
+*Rule type*: eql
+
+*Rule indices*: 
+
+* endgame-*
+* logs-crowdstrike.fdr*
+* logs-endpoint.events.process-*
+* logs-m365_defender.event-*
+* logs-sentinel_one_cloud_funnel.*
+* logs-system.security*
+* logs-windows.forwarded*
+* logs-windows.sysmon_operational-*
+* winlogbeat-*
+
+*Severity*: low
+
+*Risk score*: 21
+
+*Runs every*: 5m
+
+*Searches indices from*: now-9m ({ref}/common-options.html#date-math[Date Math format], see also <<rule-schedule, `Additional look-back time`>>)
+
+*Maximum alerts per execution*: 100
+
+*References*: None
+
+*Tags*: 
+
+* Domain: Endpoint
+* OS: Windows
+* Use Case: Threat Detection
+* Tactic: Impact
+* Resources: Investigation Guide
+* Data Source: Elastic Endgame
+* Data Source: Elastic Defend
+* Data Source: Windows Security Event Logs
+* Data Source: Microsoft Defender for Endpoint
+* Data Source: Sysmon
+* Data Source: SentinelOne
+* Data Source: Crowdstrike
+
+*Version*: 318
+
+*Rule authors*: 
+
+* Elastic
+
+*Rule license*: Elastic License v2
+
+
+==== Investigation guide
+
+
+
+*Triage and analysis*
+
+
+
+*Investigating Backup Deletion with Wbadmin*
+
+
+Windows 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.
+
+This rule identifies the deletion of the backup catalog using the `wbadmin.exe` utility.
+
+
+*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.
+- Assess whether this behavior is prevalent in the environment by looking for similar occurrences across hosts.
+- Check if any files on the host machine have been encrypted.
+
+
+*False positive analysis*
+
+
+- Administrators can use this command to delete corrupted catalogs, but overall the activity is unlikely to be legitimate.
+
+
+*Related rules*
+
+
+- Third-party Backup Files Deleted via Unexpected Process - 11ea6bec-ebde-4d71-a8e9-784948f8e3e9
+- Volume Shadow Copy Deleted or Resized via VssAdmin - b5ea4bfe-a1b2-421f-9d47-22a75a6f2921
+- Volume Shadow Copy Deletion via PowerShell - d99a037b-c8e2-47a5-97b9-170d076827c4
+- Volume Shadow Copy Deletion via WMIC - dc9c1f74-dac3-48e3-b47f-eb79db358f57
+
+
+*Response and remediation*
+
+
+- Initiate the incident response process based on the outcome of the triage.
+- Consider isolating the involved host to prevent destructive behavior, which is commonly associated with this activity.
+- 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.
+- 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.
+- If any backups were affected:
+  - Perform data recovery locally or restore the backups from replicated copies (cloud, other servers, etc.).
+- 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).
+
+
+==== Rule query
+
+
+[source, js]
+----------------------------------
+process where host.os.type == "windows" and event.type == "start" and
+  (process.name : "wbadmin.exe" or ?process.pe.original_file_name == "WBADMIN.EXE") and
+  process.args : ("catalog", "backup", "systemstatebackup") and process.args : "delete"
+
+----------------------------------
+
+*Framework*: MITRE ATT&CK^TM^
+
+* Tactic:
+** Name: Impact
+** ID: TA0040
+** Reference URL: https://attack.mitre.org/tactics/TA0040/
+* Technique:
+** Name: Data Destruction
+** ID: T1485
+** Reference URL: https://attack.mitre.org/techniques/T1485/
+* Technique:
+** Name: Inhibit System Recovery
+** ID: T1490
+** Reference URL: https://attack.mitre.org/techniques/T1490/

docs/detections/prebuilt-rules/downloadable-packages/8-18-5/prebuilt-rule-8-18-5-microsoft-azure-or-mail-sign-in-from-a-suspicious-source.asciidoc

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+[[prebuilt-rule-8-18-5-microsoft-azure-or-mail-sign-in-from-a-suspicious-source]]
+=== Microsoft Azure or Mail Sign-in from a Suspicious Source
+
+This rule correlate Azure or Office 356 mail successful sign-in events with network security alerts by source.ip. Adversaries may trigger some network security alerts such as reputation or other anomalies before accessing cloud resources.
+
+*Rule type*: esql
+
+*Rule indices*: None
+
+*Severity*: high
+
+*Risk score*: 73
+
+*Runs every*: 5m
+
+*Searches indices from*: now-60m ({ref}/common-options.html#date-math[Date Math format], see also <<rule-schedule, `Additional look-back time`>>)
+
+*Maximum alerts per execution*: 100
+
+*References*: None
+
+*Tags*: 
+
+* Domain: Cloud
+* Domain: SaaS
+* Data Source: Azure
+* Data Source: Entra ID
+* Data Source: Entra ID Sign-in Logs
+* Data Source: Microsoft 365
+* Data Source: Microsoft 365 Audit Logs
+* Use Case: Identity and Access Audit
+* Use Case: Threat Detection
+* Tactic: Initial Access
+* Resources: Investigation Guide
+* Rule Type: Higher-Order Rule
+
+*Version*: 2
+
+*Rule authors*: 
+
+* Elastic
+
+*Rule license*: Elastic License v2
+
+
+==== Investigation guide
+
+
+
+*Triage and analysis*
+
+
+
+*Investigating Microsoft Azure or Mail Sign-in from a Suspicious Source*
+
+
+
+*Possible investigation steps*
+
+
+- Investiguate all the alerts associated with the source.ip.
+  - Verify the network security alert details associated with this source.ip.
+  - Verify all sign-in events associated with this source.ip.
+  - Consider the source IP address and geolocation for the involved user account.
+  - Consider the device used to sign in. Is it registered and compliant?
+- Investigate other alerts associated with the user account during the past 48 hours.
+- Contact the account owner and confirm whether they are aware of this activity.
+- Check if this operation was approved and performed according to the organization's change management policy.
+- If you suspect the account has been compromised, scope potentially compromised assets by tracking servers, services, and data accessed by the account in the last 24 hours.
+
+
+*Response and remediation*
+
+
+- Initiate the incident response process based on the outcome of the triage.
+- Disable or limit the account during the investigation and response.
+- Identify the possible impact of the incident and prioritize accordingly; the following actions can help you gain context:
+    - Identify the account role in the cloud environment.
+    - Assess the criticality of affected services and servers.
+    - Work with your IT team to identify and minimize the impact on users.
+    - Identify if the attacker is moving laterally and compromising other accounts, servers, or services.
+    - Identify any regulatory or legal ramifications related to this activity.
+- Investigate credential exposure on systems compromised or used by the attacker to ensure all compromised accounts are identified. Reset passwords or delete API keys as needed to revoke the attacker's access to the environment. Work with your IT teams to minimize the impact on business operations during these actions.
+- Check if unauthorized new users were created, remove unauthorized new accounts, and request password resets for other IAM users.
+- Consider enabling multi-factor authentication for users.
+- Follow security best practices https://docs.microsoft.com/en-us/azure/security/fundamentals/identity-management-best-practices[outlined] by Microsoft.
+- Determine the initial vector abused by the attacker and take action to prevent reinfection via 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).
+
+==== Setup
+
+
+The Azure Fleet integration, Office 365 Logs Fleet integration, Filebeat module, or similarly structured data is required to be compatible with this rule.
+
+==== Rule query
+
+
+[source, js]
+----------------------------------
+FROM logs-*, .alerts-security.*
+// query runs every 1 hour looking for activities occured during last 8 hours to match on disparate events
+| where @timestamp > NOW() - 8 hours
+// filter for Azure or M365 sign-in and External Alerts with source.ip not null
+| where TO_IP(source.ip) is not null and (event.dataset in ("o365.audit", "azure.signinlogs") or kibana.alert.rule.name == "External Alerts") and
+// exclude private IP ranges
+  not CIDR_MATCH(TO_IP(source.ip), "10.0.0.0/8", "127.0.0.0/8", "169.254.0.0/16", "172.16.0.0/12", "192.0.0.0/24", "192.0.0.0/29", "192.0.0.8/32", "192.0.0.9/32", "192.0.0.10/32", "192.0.0.170/32", "192.0.0.171/32", "192.0.2.0/24", "192.31.196.0/24", "192.52.193.0/24", "192.168.0.0/16", "192.88.99.0/24", "224.0.0.0/4", "100.64.0.0/10", "192.175.48.0/24","198.18.0.0/15", "198.51.100.0/24", "203.0.113.0/24", "240.0.0.0/4", "::1","FE80::/10", "FF00::/8")
+| keep source.ip, event.action, event.outcome, event.dataset, kibana.alert.rule.name, event.category
+// split alerts to 3 buckets -  M365 mail access, azure sign-in and network related external alerts like NGFW and IDS
+| eval mail_access_src_ip = case(event.dataset == "o365.audit" and event.action == "MailItemsAccessed" and event.outcome == "success", TO_IP(source.ip), null),
+  azure_src_ip = case(event.dataset == "azure.signinlogs" and event.outcome == "success", TO_IP(source.ip), null),
+  network_alert_src_ip = case(kibana.alert.rule.name == "External Alerts" and not event.dataset in ("o365.audit", "azure.signinlogs"), TO_IP(source.ip), null)
+// aggregated alerts count by bucket and by source.ip
+| stats total_alerts = count(*), is_mail_access = COUNT_DISTINCT(mail_access_src_ip), is_azure = COUNT_DISTINCT(azure_src_ip), unique_dataset = COUNT_DISTINCT(event.dataset),is_network_alert = COUNT_DISTINCT(network_alert_src_ip), datasets = VALUES(event.dataset), rules = VALUES(kibana.alert.rule.name), cat = VALUES(event.category) by source_ip = TO_IP(source.ip)
+// filter for cases where there is a successful sign-in to azure or m365 mail and the source.ip is reported by a network external alert.
+| where is_network_alert  > 0 and unique_dataset >= 2 and (is_mail_access > 0 or is_azure > 0) and total_alerts <= 100
+
+----------------------------------
+
+*Framework*: MITRE ATT&CK^TM^
+
+* Tactic:
+** Name: Initial Access
+** ID: TA0001
+** Reference URL: https://attack.mitre.org/tactics/TA0001/
+* Technique:
+** Name: Valid Accounts
+** ID: T1078
+** Reference URL: https://attack.mitre.org/techniques/T1078/