diff --git a/rules/cloud/google/gcp_firewall_rule_deleted.yml b/rules/cloud/google/gcp_firewall_rule_deleted.yml new file mode 100644 index 000000000..c323bfdb5 --- /dev/null +++ b/rules/cloud/google/gcp_firewall_rule_deleted.yml @@ -0,0 +1,30 @@ +# Rule version v1.0.0 + +dataTypes: + - google +name: GCP Firewall Rule Deleted +impact: + confidentiality: 2 + integrity: 2 + availability: 3 +category: Impact +technique: "T1562 - Impair Defenses" +adversary: origin +references: + - https://cloud.google.com/firewall/docs/rules/create-manage#deleting_a_firewall_rule + - https://cloud.google.com/logging/docs/audit/cal-categories#compute_engine + - https://attack.mitre.org/techniques/T1562/ +description: | + Detects deletion of a GCP VPC firewall rule. Attackers may delete security rules (such as egress filters or blocking rules) to facilitate data exfiltration or lateral movement. Unexpected firewall deletions should be investigated promptly. + + Next Steps: + 1. Verify if the deletion was part of an authorized change window + 2. Identify the deleted firewall rule's purpose (security blocking vs routine rule) + 3. Check if the user has a legitimate reason for the change + 4. Re-create the rule if it was a security control + 5. Review other compute firewall changes in the same time window + 6. Check if the user's account shows signs of compromise +where: | + equals("log.protoPayloadServiceName", "compute.googleapis.com") && + equals("log.protoPayloadMethodName", "v1.compute.firewalls.delete") && + exists("origin.user")