We have been observing a malvertising campaign via Rig exploit kit delivering a cryptocurrency-mining malware and the GandCrab ransomware since July 25. On August 1, we found Rig’s traffic stream dropping a then-unknown ransomware. Delving into this seemingly new ransomware, we checked its ransom payment page in the Tor network and saw it was called Princess Evolution (detected by Trend Micro as RANSOM_PRINCESSLOCKER.B), and was actually a new version of the Princess Locker ransomware that emerged in 2016. Based on its recent advertisement in underground forums, it appears that its operators are peddling Princess Evolution as a ransomware as a service (RaaS) and are looking for affiliates.