| Refer -> [Trojan horse - Virus or malware? | Malwarebytes](https://www.malwarebytes.com/trojan) & [Trojan Horse Virus | Fortinet](https://www.fortinet.com/resources/cyberglossary/trojan-horse-virus) |
Trojan horse is a malware appearing like a legitimate program. It uses social engineering to trick users into installing it and launching the infected program in their systems.
Eg : ILOVEYOU, Conficker, Zeus, etc.
Delivery
It is delivered via emails, social-engineering, or through shady websites.
Since Trojan is a delivery strategy to deliver a threat, it can either be a tool for other malwares or a standalone malware by itself.
Consequence
A computer infected by Trojan becomes a zombie computer. Hackers can control it to share the malware across many devices to create a botnet.
Types
- Backdoor trojan : Creates remote access to system; used after a system hacking for ease of access.
- Spyware : Watches you enter sensitive info. to steal them.
- Downloader trojan : Downloads adware, ransomware or keylogger.
- Distributed Denial of Service [DDoS] trojan : Overloads a network with traffic by sending multiple requests from a group of computers [botnet] to cause a Denial of Service [DoS].
- Rootkit trojan : Acts as carrier for a rootkit; stops malicious programs from being detected.