Trojans: This has been a dominant type of malware over the last few years, and it only keeps increasing in terms of its share of the “malwareverse” (just coined that one for “the realm of malware” 🙂 ). It has gone from 56% in early 2011 to 78% in late 2014.

One interesting type of Trojan is labeled Ransomware: Aptly named because this type of infection usually locks your computer or your data (by encrypting it) and then asks for a ransom to unlock it. A “rising star”, this type of malware has been in the increase in recent times, and is one of the reasons I’ve been recently advocating having a data backup plan in place – because this type of infection usually encrypts your documents and files (rendering them useless to you) and some of them do not allow decryption by any  known methods, which means the only way to recover from such an attack (not in terms of eliminating the active threat but in terms of damage control) is to restore your data from your latest backup.

Also because some of these infections will encrypt any external hard drives attached to a computer, I have recommended in the past not to leave your external hard drive (containing your data backup) connected permanently to your computer. In other words, unless actively in the process of updating a backup, the external hard drive should not be connected to your computer.

So beware of these types of infections AND have a sound security plan in place which includes a periodically updated data backup.