Query: indicators of Shared Modules
Matching passage: T1129 Shared Modules. Tactics: execution. Description: Adversaries may execute malicious payloads via loading shared modules. Shared modules are executable files that are loaded into processes to provide access to reusable code, such as specific custom functions or invoking OS API functions (i.e., [Native API](https://attack.mitre.org/techniques/T1106)). Adversaries may use this functionality as a way to execute arbitrary payloads on a victim system. For example, adversaries can modularize functionality of their malware into shared objects that perform various functions such as managing C2 network communications or execution of specific actions on objective. The Linux & macOS module loader can load and execute shared objects from arbitrary local paths. This functionality resides in `dlfcn.h` in functions such as `dlopen` and `dlsym`. Although macOS can execute `.so` files, common practice uses `.dylib` files.(Citation: Apple Dev Dynamic Libraries)(Citation: Linux Shared Libraries)(Citation: RotaJakiro 2021 netlab360 analysis)(Citation: Unit42 OceanLotus 2017) The Windows module loader can be instructed to load DLLs from arbitrary local paths and arbitrary Universal Naming Convention (UNC) network paths. This functionality resides in `NTDLL.dll` and is part of the Windows [Native API](https://attack.mitre.org/techniques/T1106) which is called from functions like `LoadLibrary` at run time.(Citation: Microsoft DLL)
Near-miss passage: T1197 BITS Jobs. Tactics: stealth, persistence, execution. Description: 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](https://attack.mitre.org/techniques/T1559/001) (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](https://attack.mitre.org/techniques/T1059/001) and the [BITSAdmin](https://attack.mitre.org/software/S0190) tool.(Citation: Microsoft BITS)(Citation: Microsoft BITSAdmin) Adversaries may abuse BITS to download (e.g. [Ingress Tool Transfer](https://attack.mitre.org/techniques/T1105)), execute, and even clean up after running malicious code (e.g. [Indicator Removal](https://attack.mitre.org/techniques/T1070)). 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](https://attack.mitre.org/techniques/T1048).(Citation: CTU BITS Malware June 2016)