(also downloader, trojan-downloader)
Downloader trojan definition
A downloader trojan is a type of malware designed to install malicious software or files onto a victim’s device (e.g., smartphone or computer) without them knowing. A trojan is malware that disguises itself as legitimate or useful software. Downloader trojans focus on downloading and executing additional malware onto the infected system. It becomes a “hidden doorway” that allows other viruses, ransomware, or spyware to infect the device.
How downloader trojans infect devices
- The attacker makes a downloader trojan available for an unsuspecting user to download. The trojan disguises itself as a harmless or legitimate file, such as a software update or a game.
- The user downloads and runs it on their device without knowing it’s malicious.
- Once the downloader trojan is installed, it starts its malicious activities in the background.
- The downloader trojan establishes a connection with a remote server controlled by the attacker. The server contains additional malware the trojan aims to download and install.
- The trojan gets instructions from the remote server to download specific malware payloads (e.g., viruses, ransomware, or spyware).
- The trojan installs the downloaded malware onto the victim’s device without the user’s awareness.
- Once the malware is installed, it carries out various malicious activities (like corrupting files, encrypting files to demand payment, or seeing what the user types).
- Downloader trojans attempt to remain undetected by hiding their processes, modifying system files, or evading security software.
How to prevent downloader trojans
- Use reliable security software.
- Don’t open suspicious email attachments.
- Download software and files from reliable sources only.
- Be cautious when visiting websites: some may be malicious.