Masquerading: Invalid Code Signature
Adversaries may attempt to mimic features of valid code signatures to increase the chance of deceiving a user, analyst, or tool. Code signing provides a level of authenticity on a binary from the developer and a guarantee that the binary has not been tampered with. Adversaries can copy the metadata and signature information from a signed program, then use it as a template for an unsigned program. Files with invalid code signatures will fail digital signature validation checks, but they may appear more legitimate to users and security tools may improperly handle these files.
Unlike Code Signing, this activity will not result in a valid signature.
Require signed binaries.
Collect and analyze signing certificate metadata and check signature validity on software that executes within the environment, look for invalid signatures as well as unusual certificate characteristics and outliers.
- Vest, J. (2017, October 9). Borrowing Microsoft MetaData and Signatures to Hide Binary Payloads. Retrieved September 10, 2019.
- Raiu, C., and Ivanov, A. (2016, June 17). Operation Daybreak. Retrieved February 15, 2018.
- Lunghi, D., et al. (2017, December). Untangling the Patchwork Cyberespionage Group. Retrieved July 10, 2018.
- McAfee. (2015, March 2). Netwire RAT Behind Recent Targeted Attacks. Retrieved February 15, 2018.
- Kaspersky Lab's Global Research and Analysis Team. (2014, November 24). THE REGIN PLATFORM NATION-STATE OWNAGE OF GSM NETWORKS. Retrieved December 1, 2014.
- Wardle, Patrick. (2018, December 20). Middle East Cyber-Espionage analyzing WindShift's implant: OSX.WindTail (part 1). Retrieved October 3, 2019.
- Karim, T. (2018, August). TRAILS OF WINDSHIFT. Retrieved June 25, 2020.