The online advertising firm Sizmek Inc., the third-largest ad server network in the world, recently suffered a data breach. A cybercriminal was discovered selling access to a basic user account on a dark web criminal forum in Russian. The account, however, was able to modify ads, offers, and marketing analysis for several well-known business brands in the US. This access could leave the site exposed to sabotage and its users subject to possible malware. It appears that the threat actor targeted accounts of key employees, and infiltrated those accounts of past employees, vendors, and partners that were not disabled. Two frequently used methods of compromise are password spraying and “brute-force light” attacks. Sizmek CEO, Mark Grether, stated that appropriate physical, technical, and administrative safeguards have been implemented, ensuring that the protocol issue has been corrected.