Malware delivered to email accounts rose 196% in 2021 year on year, according to cybersecurity firm Trend Micro, which warns that email remains a major avenue for criminals looking to deliver malware and phish account credentials.
Some 74.1% of the all threats blocked by Trend Micro in 2021 were email threats versus its products that blocked malware delivered over websites.
Trend Micro's figures are based on detections gathered from enterprise customers that use its Cloud App Security product on top of Google Workspace and Microsoft 365, which both feature in-built anti-malware systems.
The firm saw large increases in known and unknown malware, which rose 134% and 221% respectively year on year.
Major email threats were the Emotet spam botnet, the Panda Stealer targeting cryptocurrency wallets, Qakbot, and an advanced persistent threat targeting organizations in South America.
Attacks on cryptocurrency wallets became prevalent enough through 2021 that Microsoft is now trying to push the name "cryware" for this type of information-stealing malware.
Ransomware threats delivered through email declined in 2021 due to attackers shifting from mass campaigns with small demands aimed at individuals to highly targeted efforts involving larger ransom sums to decrypt files.