Shamoon’s comeback early last week was not marked by one, but two occurrences of the data-wiping malware. The second sighting observed a different sample that could indicate a follow-up to the initial attack. About 80% of this new sample of Shamoon, aka Disstrack, is similar to earlier versions of the malware. Researchers at Anomali Labs say the trigger date is still set in the past but to December 12, 2017, five days later than the one in the variant identified earlier. The initial infection vector for the Shamoon strains discovered this month remains unknown.
Source: https://www.bleepingcomputer.com/news/security/shamoon-disk-wiper-returns-with-second-sample-uncovered-this-month/