Archive Collected Data: Archive via Library
An adversary may compress or encrypt data that is collected prior to exfiltration using 3rd party libraries. Many libraries exist that can archive data, including Python rarfile , libzip , and zlib . Most libraries include functionality to encrypt and/or compress data.
Some archival libraries are preinstalled on systems, such as bzip2 on macOS and Linux, and zip on Windows. Note that the libraries are different from the utilities. The libraries can be linked against when compiling, while the utilities require spawning a subshell, or a similar execution mechanism.
This type of attack technique cannot be easily mitigated with preventive controls since it is based on the abuse of system features.
Monitor processes for accesses to known archival libraries. This may yield a significant number of benign events, depending on how systems in the environment are typically used.
Consider detecting writing of files with extensions and/or headers associated with compressed or encrypted file types. Detection efforts may focus on follow-on exfiltration activity, where compressed or encrypted files can be detected in transit with a network intrusion detection or data loss prevention system analyzing file headers.
- mkz. (2020). rarfile 3.1. Retrieved February 20, 2020.
- D. Baron, T. Klausner. (2020). libzip. Retrieved February 20, 2020.
- madler. (2017). zlib. Retrieved February 20, 2020.
- Dunwoody, M. and Carr, N.. (2016, September 27). No Easy Breach DerbyCon 2016. Retrieved October 4, 2016.
- Kaspersky Lab's Global Research & Analysis Team. (2014, August 06). The Epic Turla Operation: Solving some of the mysteries of Snake/Uroboros. Retrieved November 7, 2018.
- Gross, J. (2016, February 23). Operation Dust Storm. Retrieved September 19, 2017.
- Grunzweig, J.. (2017, April 20). Cardinal RAT Active for Over Two Years. Retrieved December 8, 2018.
- Shulmin, A., Yunakovsky, S. (2017, April 28). Use of DNS Tunneling for C&C Communications. Retrieved November 5, 2018.
- Lee, B. Grunzweig, J. (2015, December 22). BBSRAT Attacks Targeting Russian Organizations Linked to Roaming Tiger. Retrieved August 19, 2016.
- GReAT. (2019, April 10). Project TajMahal – a sophisticated new APT framework. Retrieved October 14, 2019.
- Counter Threat Unit Research Team. (2017, June 27). BRONZE UNION Cyberespionage Persists Despite Disclosures. Retrieved July 13, 2017.
- Novetta Threat Research Group. (2016, February 24). Operation Blockbuster: Remote Administration Tools & Content Staging Malware Report. Retrieved March 16, 2016.
- Sherstobitoff, R. (2018, February 12). Lazarus Resurfaces, Targets Global Banks and Bitcoin Users. Retrieved February 19, 2018.
- Wikipedia. (2016, March 31). List of file signatures. Retrieved April 22, 2016.