Updating Adobe Flash is apparently such a regular task for computer users that hackers are able to take advantage of the familiarity and slip in cryptocurrency mining malware into fake Flash updates. Once installed, the malware works in the background, using the computer’s processing power to mine cryptocurrency (Monero, in this specific malware example). One differentiator of this false Adobe Flash update, however, is that is actually updates Adobe Flash, which helps keep the malware hidden, as the user is less likely to notice that anything has gone wrong, which is an essential component in crypto mining schemes that harness the power of vast numbers of personal computers. Researchers have not been able to estimate the scale of this malware beyond the 113 cases they have identified.
Source: This Malware Pretends to Be a Flash Update But Is Really Mining Cryptocurrency – Nextgov