Miners are malicious programmes designed to steal cryptocurrency from infected devices. They’re often installed without users’ knowledge and then begin slowly siphoning off various types of cryptocoins; in some cases the miners walk away with millions. While miners became a popular tool in cybercriminals’ arsenals beginning in 2018, their popularity had steadily declined over the course of 2020.

However, according to Kaspersky’s Malware Q1 2021 report, that changed in the first quarter of 2021. From February to March 2021, the number of unique modifications of miners more than quadrupled from 3,815 to 16,934. In total, Kaspersky researchers discovered 23,894 new modifications of miners in Q1 2021. 

The number of Kaspersky users that encountered miners on their devices steadily increased as well—from 187,746 in January to 200,045 users in March 2021. In total, 432,171 unique users encountered miners in Q1 2020.

“It’s too early to say for sure if the trend we’ve noted in Q1 2021 is here to stay. However, it does seem that the increase in the value of Bitcoin and other cryptocurrency has sparked a renewed interest in miners. If the crypto markets remains strong this year, it’s like we’ll continue to see more instances of users encountering miners,” comments Evgeny Lopatin, security expert at Kaspersky.

Other notable trends from the report include a decrease in the number of users encountering both mobile and PC banking Trojans and an increase in the number of modifications of ransomware Trojans—from 3,096 in Q4 2020 to 4,354 in Q1 2021.

You can read the full report on Securelist.

To reduce the risk of being exposed to miners, Kaspersky experts recommend the following:

• Install a strong security solution on your computer.
• Since miners are often distributed as “riskware”, they are not automatically blocked by security solutions. You may want to configure your security solution’s settings to block any “riskware” programmes.
• Always keep software updated on all the devices you use. To prevent miners from exploiting vulnerabilities, use tools that can automatically detect vulnerabilities and download and install patches.
• Choose to install applications from legitimate sources (e.g. official app stores).