Technical Tip: Using FortiAnalyzer to detect activities related to the JetBrains TeamCity Authentication Bypass Attack | CVE-2023-42793

[ck_FTNT]

Description	This article describes how to use a custom event handler in FortiAnalyzer to raise alerts for incident response related to attacks that attempt to leverage the JetBrains TeamCity Authentication Bypass Attack. A report is also provided to gain historical visibility into the logs. Note that this article provides alpha files which are automatically generated. The article will be continually updated as more information becomes available.
Scope	This article contains the files necessary to load an event handler and report into the FortiAnalyzer for either a Fabric ADOM or a FortiGate ADOM. The Fabric report and event handler leverage logs from other Fortinet products that can be used to detect the attack in addition to FortiGate logs. For more information about this attack, see the following FortiGuard Outbreak Alert: JetBrains TeamCity Authentication Bypass Attack.
Solution	What is included in Fortinet_JetBrains TeamCity Authentication Bypass Attack.zip: JetBrains TeamCity Authentication Bypass Attack.json. This event handler helps identify JetBrains TeamCity Authentication Bypass Attack detected by FortiGate and other Fortinet products. JetBrains TeamCity Authentication Bypass Attack.dat. This report displays the findings on JetBrains TeamCity Authentication Bypass Attack attacks from FortiGate and other Fortinet products.  fgt_JetBrains TeamCity Authentication Bypass Attack.json. The event handler for FortiGate ADOMs is configured for FortiGate logs only. fgt_JetBrains TeamCity Authentication Bypass Attack_report.dat. The report for FortiGate ADOMs includes FortiGate charts only. Steps: Download the Fortinet_JetBrains TeamCity Authentication Bypass Attack.zip file (contains 4 files). Unzip Fortinet_JetBrains TeamCity Authentication Bypass Attack.zip. Import JetBrains TeamCity Authentication Bypass Attack_event-handler.json or fgt_JetBrains TeamCity Authentication Bypass Attack_event-handler.json event handler: Choose an ADOM (if ADOMs are enabled). The ADOM may have the Fabric or FortiGate type. Choose the FortiSOC module.  Select Event Handler List. Select the Import option under More. Select the appropriate event handler depending on the ADOM type. Result: The event handler is enabled and will be triggered if the appropriate logs are received following the import of the event handler.  Edit the event handler to customize the notification section. Import JetBrains TeamCity Authentication Bypass Attack_report.dat or fgt_JetBrains TeamCity Authentication Bypass Attack_report.dat to Reports: Choose an ADOM (if ADOMs are enabled). The ADOM may have the Fabric or FortiGate type. Choose the Report module. Select the Import option under 'More'. Select the appropriate file for the ADOM type to add the report to the ADOM. Result:  The JetBrains TeamCity Authentication Bypass Attack_report can be run anytime as determined by an admin user.