A Trojan is a malicious program misguided as some very important application. Trojans comes on the backs of other programs and are installed on a system without the User’s knowledge. Trojans are malicious pieces of code used to install hacking software on a target system and aid the Hacker in gaining and retaining access to that system. Trojans and their counterparts are important pieces of the Hacker’s tool-kit.
Purpose of Trojans
- Steal information such as passwords, security codes, credit card information using keyloggers.
- Use victim´s PC as a botnet to perform DDoS attacks.
- Delete or replace OS critical files.
- Generate fake traffic to create DoS.
- Download spyware, adware and malware.
- Record screenshots, audio and video of victim´s PC.
- Disable firewall and antivirus.
- Infect victim´s PC as a proxy server for relaying attacks.
- Use victim´s PC as a botnet to perform DoS, spamming and blasting email messages.
There are various types of Trojans like:
- Hypervisor Trojan
- HTTP/HTTPS Trojan
- Remote access Trojan
- FTP Trojans
- VNC Trojans
- Banking Trojans
- DOM based Trojan
- Destructive Trojan
- Botnet Trojan
- Proxy Trojan
- Data hiding Trojan
Countermeasures:
- Avoid opening emails from unknown users.
- Do not download free software’s from untrusted sites.
- Always use a Premium Antivirus.
- Keep OS updates.
- Always upgrade and keep firewalls, IDS and anti-virus updated with latest patches and signatures.
- Block all unnecessary ports.