In total we detected 37 unique files and 218 detected objects, including executables and archives containing malware associated with the Equation Group. Looking at this metadata during current investigation we were tempted to include the full list of detected files and file paths into current report, however, according to our ethical standards, as well as internal policies, we cannot violate our users’ privacy. This was a hard decision, but should we make an exception once, even for the sake of protecting our own company’s reputation, that would be a step on the route of giving up privacy and freedom of all people who rely on our products. Unless we receive a legitimate request originating from the owner of that system or a higher legal authority, we cannot release such information.
The file paths observed from these detections indicated that a developer of Equation had plugged in one or more removable drives, AV signatures fired on some of executables as well as archives containing them, and any files detected (including archives they were contained within) were automatically pulled back. At this point in time, we felt confident we had found the source of the story fed to Wall Street Journal and others. Since this type of event clearly does not happen often, we believe some dates were mixed up or not clear from the original source of the leak to the media.
Our next task was to try and answer what may have happened to the data that was pulled back. Clearly an archive does not contain only those files that triggered, and more than likely contained a possible treasure trove of data pertaining to the intrusion set. It was soon discovered that the actual archive files themselves appear to have been removed from our storage of samples, while the individual files that triggered the alerts remained.
Upon further inquiring about this event and missing files, it was later discovered that at the direction of the CEO, the archive file, named “[undisclosed].7z” was removed from storage. Based on description from the analyst working on that archive, it contained a collection of executable modules, four documents bearing classification markings, and other files related to the same project. The reason we deleted those files and will delete similar ones in the future is two-fold; We don’t need anything other than malware binaries to improve protection of our customers and secondly, because of concerns regarding the handling of potential classified materials. Assuming that the markings were real, such information cannot and will not consumed even to produce detection signatures based on descriptions.
This concern was later translated into a policy for all malware analysts which are required to delete any potential classified materials that have been accidentally collected during anti-malware research or received from a third party. Again to restate: to the best of our knowledge, it appears the archive files and documents were removed from our storage, and only individual executable files (malware) that were already detected by our signatures were left in storage. Also, it is very apparent that no documents were actively “detected on” during this process. In other words, the only files that fired on specific Equation signatures were binaries, contained within an archive or outside of it. The documents were inadvertently pulled back because they were contained within the larger archive file that alerted on many Equation signatures. According to security software industry standards, requesting a copy of an archive containing malware is a legitimate request, which often helps security companies locate data containers used by malware droppers (i.e. they can be self-extracting archives or even infected ISO files).
