Detecting Windows BITS abuse
Windows Background Intelligent Transfer Service (BITS) is a low-bandwidth, asynchronous file transfer mechanism exposed through Component Object Model (COM). BITS is commonly used by updaters, messengers, and other applications which prefer to operate in the background (using available idle bandwidth) without interrupting other networked applications. File transfer tasks are implemented as BITS jobs, which contain a queue of one or more file operations. The interface to create and manage BITS jobs is accessible through PowerShell and the BITSAdmin tool.
Attackers may abuse BITS to download, execute, and clean up after running malicious code. BITS tasks are self-contained in the BITS job database, without new files or registry modifications, and are often permitted by host firewalls. BITS-enabled execution may also enable persistence by creating long-standing jobs, since the default maximum lifetime is 90 days and extendable, or invoking an arbitrary program when a job completes or errors, including after system reboots.
These searches allow you to detect and investigate unusual activities that might indicate BITS abuse.
Required data
- Endpoint data with information on process that includes the name of the process responsible for the changes from your endpoints. Use this data to populate the Processes node of the Endpoint data model in the Common Information Model (CIM). For information on installing and using the CIM, see the Common Information Model documentation.
How to use Splunk software for this use case
- Next steps
In addition, these Splunk resources might help you understand and implement this use case:
- Blog: Threat Hunting with Splunk: Hands-on Tutorials for the Active Hunter
- If you are a Splunk Enterprise Security customer, you can also get help from the Security Research team's support options on GitHub.