Trojan.DNSChanger

Short bio

Trojan.DNSchanger is the generic detection for Trojans that change a system’s DNS settings without the users’ knowledge or consent.

Type and source of infection

Once the systems are infected by Trojan.DNSChanger and their DNS settings modified, systems use foreign DNS servers set up by the threat actors. Infected systems that attempt to access specific sites are redirected to sites specified by threat actors.

Domain Name System (DNS), is known as an Internet standard for the assigning of Internet Protocol (IP) addresses to domain names. Simply put, DNS interprets human-friendly host names to PC-friendly IP addresses.

It is common for users to automatically use DNS servers operated by their ISPs. Users who prefer more secure, faster, and reliable DNS servers usually go with a third-party service as ISP-administered DNS servers can be slow and unreliable.

DNS changers/hijackers are usually bundled with other malware, such as rootkits, as seen in TDSS. Fake antivirus (FakeAV) programs have also been used to spread DNS changer Trojans, as seen in Rove Digital.

Protection

Malwarebytes protects users from Trojan.DNSChanger by using real-time protection.

Malwarebytes blocks Trojan.DNSChanger

Remediation

Malwarebytes can detect and remove Trojan.DNSChanger without further user interaction.

1. Please download Malwarebytes to your desktop.
2. Double-click mb3-setup-consumer-{version}.exe and follow the prompts to install the program.
3. Then click Finish.
4. Once the program has fully updated, select Scan Now on the Dashboard. Or select the Threat Scan from the Scan menu.
5. If another update of the definitions is available, it will be implemented before the rest of the scanning procedure.
6. When the scan is complete, make sure that all Threats are selected, and click Remove Selected.
7. Restart your computer when prompted to do so.

A reboot is often required to flush the “poisoned” DNS cache. Malwarebytes will prompt you to do this if needed.

Related blog content

DNS Hijacks: What to Look For
10 easy ways to prevent malware infection