Firefox’s add-on review process, while more stringent than Chrome’s initially, struggled with the scale of popular extensions. SaveFrom.net Helper exploited this by using and time-bombed malicious code (activating 30 days after review).
Ironically, many loyal users blamed Mozilla for “censoring their freedom to download,” not realizing their browsers had been part of a botnet. Forums on Reddit and Mozilla Support were flooded with complaints until technical users posted packet captures proving the malware. savefrom.net helper firefox