Crypto-miners are quietly colonising computers

Subscribe to enjoy similar stories.MINING A CRYPTOCURRENCY can be an expensive business. Producing new coins, also known as tokens, can require computers to solve cryptographic puzzles, which takes large amounts of power. One way to keep costs down is to relocate mines to wherever electricity is cheapest.

Cheaper still is having others foot the bill. An unsuspecting organisation’s power can be hijacked by stacking computers in a crawlspace or storage room, for example. Such operations, however, are regularly discovered, and culprits risk penalties and confiscated kit.A less risky and more scalable approach is to steal power by remotely sneaking crypto-mining software onto other people’s computers.

Crypto-jacking, as this trick is known, is booming. Over the course of 2025, instances jumped by about 20%, according to a note in November from GreyNoise, an American security firm. Victims take quite a hit.

A study published in 2022 by Sysdig, a security company based in San Francisco, estimates that every dollar in crypto thus generated costs victims an average of $53 in computing expenses.Part of the surge is due to the high value of cryptocurrencies in recent years (although there has been a drop in 2026). The barriers to crypto-jacking are also relatively low. The requisite software is readily obtained from underground web forums, says a specialist with Interpol’s cybercrime unit in Singapore who required anonymity to comment on operations.

And installing such software on computers is less challenging than stealing data, or, in the case of ransomware, holding it hostage. The upshot is that crypto-jacking shows no sign of going away.Among the most useful tools in crypto-jackers’ arsenal are web-crawling bots. These packets