The three firms, which serve customers in industry, including owners of critical infrastructure, were the subject of a warning from the Department of Homeland Security. DHS's ICS CERT said it was alerted to compromises of the vendors' by researchers at the security firms Symantec and F-Secure. DHS said it is analyzing malware associated with the attacks. The malicious software, dubbed "Havex" was being spread by way of so-called "watering hole" attacks that involved compromises of vendors web sites. According to Symantec, the malware targeted energy grid operators, major electricity generation firms, petroleum pipeline operators, and energy industry industrial equipment providers. Most of the victims were located in the United States, Spain, France, Italy, Germany, Turkey, and Poland.
It turns out there's a significant flaw in the approach. Because both the medallion and hack numbers are structured in predictable patterns, it was trivial to run all possible iterations through the same MD5 algorithm and then compare the output to the data contained in the 20GB file. Software developer Vijay Pandurangan did just that, and in less than two hours he had completely de-anonymized all 173 million entries.