Find sigma rule 
Attack: BITS Jobs
Adversaries may abuse BITS jobs to persistently execute code and perform various background tasks. Windows Background Intelligent Transfer Service (BITS) is a low-bandwidth, asynchronous file transfer mechanism exposed through Component Object Model (COM).(Citation: Microsoft COM)(Citation: Microsoft BITS) BITS is commonly used by updaters, messengers, and other applications preferred 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.(Citation: Microsoft BITS)(Citation: Microsoft BITSAdmin)
Adversaries may abuse BITS to download (e.g. Ingress Tool Transfer), execute, and even clean up after running malicious code (e.g. Indicator Removal). BITS tasks are self-contained in the BITS job database, without new files or registry modifications, and often permitted by host firewalls.(Citation: CTU BITS Malware June 2016)(Citation: Mondok Windows PiggyBack BITS May 2007)(Citation: Symantec BITS May 2007) BITS enabled execution may also enable persistence by creating long-standing jobs (the default maximum lifetime is 90 days and extendable) or invoking an arbitrary program when a job completes or errors (including after system reboots).(Citation: PaloAlto UBoatRAT Nov 2017)(Citation: CTU BITS Malware June 2016)
BITS upload functionalities can also be used to perform Exfiltration Over Alternative Protocol.(Citation: CTU BITS Malware June 2016)
MITRE
Tactic
- defense-evasion
- persistence
technique
- T1197
Test : Bits download using desktopimgdownldr.exe (cmd)
OS
- windows
Description:
This test simulates using desktopimgdownldr.exe to download a malicious file instead of a desktop or lockscreen background img. The process that actually makes the TCP connection and creates the file on the disk is a svchost process (“-k netsvc -p -s BITS”) and not desktopimgdownldr.exe. See https://labs.sentinelone.com/living-off-windows-land-a-new-native-file-downldr/
Executor
command_prompt
Sigma Rule
- proc_creation_win_desktopimgdownldr_susp_execution.yml (id: bb58aa4a-b80b-415a-a2c0-2f65a4c81009)