Welcome to the Avast Q4’21 Threat Report! Just like the rest of last year, Q4 was packed with many surprises and plot twists in the threat landscape. Let me highlight some of them.
We all learned how much impact a small library for logging can have. Indeed, I’m referring to the Log4j Java library, where a vulnerability was discovered and immediately exploited. The rate at which malware operators exploited the vulnerability was stunning. We observed coinminers, RATs, bots, ransomware, and of course APTs abusing the vulnerability faster than a software vendor could say “Am I also using this Log4j library somewhere below?”. In a nutshell: Christmas came early for malware authors.
Original credits: XKCD
Furthermore, in my Q3’21 foreword, I mentioned the take-down of botnet kingpin, Emotet. We were curious which bot would replace it… whether it would be Trickbot, IcedID, or one of the newer ones. But the remaining Emotet authors had a different opinion, and pretty much said “The king is dead, long live the king!”, they rewrote several Emotet parts, revived their machinery, and took the botnet market back with the latest Emotet reincarnation.
Out of the other Q4’21 trends, I would like to highlight an