According to the data reported by the network security company SonicWall, the agency recorded a total of 332.3 million encryption hijacking attacks in the first half of 2023, an increase of 399% compared with the whole of last year.
This figure is higher than the number of cryptojacking attacks in 2020, 2021 and 2022 combined.
Cryptojacking involves using servers and computer equipment belonging to others to mine digital assets, with the privacy-focused Monero coin being the most popular, SonicWall said.
Affected people may not even realize they are victims, they may just feel that their machines are running slower than usual.
According to Spencer Starkey, vice president of SonicWall Europe, the Middle East and Africa, the biggest symptoms of cryptojacking include slow device response, abnormally high electricity bills, and overheating batteries that cause excessive fan usage.
In contrast to ransomware or banking Trojans, cryptojackers aim to remain undetected for as long as possible.