Trojans? What are they?
The main objective of this type of malware is to install other applications on the infected computer, so it can be controlled from other computers.
Trojans do not spread by themselves, and as their name suggests, like the astute Greeks in their attack on Troy, these malicious codes reach computers in the guise of an apparently harmless program, which, in many cases, when executed releases a second program, the Trojan itself.
Currently, the percentage of malware traffic represented by the Trojans worldwide is: Worm: 14.04%
What do they do?
The effects of Trojans can be highly dangerous. Like viruses, they can destroy files or information on hard disks. They can also capture and resend confidential data to an external address or open communication ports, allowing an intruder to control the computer remotely. Additionally, they can capture keystrokes or record passwords entered by users. Given all these characteristics, they are frequently used by cyber-crooks, for example, to steal confidential banking information.
Evolution
Trojans were designed initially to cause as much damage as possible on the compromised computer. They were designed to format disks or eliminate system files, although they were not widely noticed, as at that time malware creators were looking to cause widespread epidemics, and Trojans could not spread by themselves. One such example was Autorooter.
In recent years, thanks to the massive uptake of the Internet, the trend has changed and cyber-crooks have seen the use of this type of malware for stealing bank details, usernames and passwords, personal information, etc. In fact, this has led to the creation of new categories of malware: Banker Trojans and Spyware.
Within the banker Trojan category, one example which has been highly active recently is Trj/Sinowal, a kit sold on some Russian forums which allows the buyer to create bespoke banker Trojans to launch an attack.
At PandaLabs we have observed a worrying increase in the production of banker Trojans, as illustrated in the following graph. Trojans currently account for 70% of all malware we receive at the laboratory.
How can you protect yourself?
To protect yourself against this ubiquitous type of malware, we offer a series of practical tips: