Backdoor.Flashback.39, the piece of malware designed to target computers running Mac OS X, caused a lot of headaches for Mac users, especially because one of the Java vulnerabilities it exploited remained unpatched by Apple.
Security experts have found that even after Apple patched the flaw, the cybercriminals behind the operation didn't seem to be discouraged.
Researchers from Russian security firm Doctor Web analyzed the malicious element and determined that the infection begins when users are redirected to shady sites from compromised domains.
The exploit then saves an executable onto the infected Mac machine. This executable file connects to a remote server from which it downloads and executes the final payload.