First off, users should avoid downloading Transmission BitTorrent version 2.90, the file-sharing software that delivered the ransomware — a form of malware that encrypts certain files and data until users submit a bitcoin payment.
Mac users can also make sure Apple's own malware protection feature, XProtect, is enabled. That feature blocks known malicious software from being installed on the tech giant's computers.
The ransomware, dubbed KeRanger, was detected by security company Palo Alto Networks on March 4, specifically on computers with Transmission BitTorrent installed, Palo Alto said Sunday.
In this instance, the ransomware authors asked victims to pay one bitcoin (or about $414 as of Monday) in exchange for their data.
In an email to CNBC, an Apple spokesperson said the company has updated XProtect and pulled Transmission BitTorrent's developer certificate, so that no one can install the infected app.