One of the largest botnets ever is gone, as an international law enforcement operation led by the U.S. Justice Department shut down the 911 S5 botnet. A botnet is a collection of compromised computers that hackers use to stage cyberattacks or commit fraud, and this massive network infected millions of Windows computers, amassing over 19 million IP addresses which 911 S5 then rented out to other crooks.
And you could have been part of it without even knowing. That’s because the 911 S5 botnet was built by convincing users to install free VPN software, or by bundling malware with other applications, so you may have installed it without realizing it was malicious. When you installed one of the botnet’s applications, your computer became a proxy for criminal activity: online crooks would pay 911 S5 to use these compromised computers, making it seem like their actions came from a different location. By using the botnet, cybercriminals obscured their location – much the same way we might do with a VPN – which made it easier to commit fraud or transmit illicit materials.
Read more: How to Protect Your Privacy on Public WiFi Networks
While the worst of the threat is gone, your computer could still have 911 S5 malware. Here's how to find out if your system was part of the 911 S5 botnet and get rid of any malware. The botnet was spread by at least six different free VPN apps: MaskVPN, DewVPN, PaladinVPN, ProxyGate, ShieldVPN, and ShineVPN. Even though the network has been shut down, you should check your system and make sure none of these applications are installed. To do so, go to the search box in the Windows taskbar and type the following app names one at a time to see if they’re on your system:
- MaskVPN
- DewVPN
- PaladinVPN
- ProxyGate
- ShieldVPN
- ShineVPN
If you see any of these apps, right click its name and select Uninstall, removing the app. If you're having trouble, the FBI has detailed instructions that can help you track down these malicious apps.
VPNs can keep you safe online, particularly if you’re using public WiFi, because they encrypt your traffic and protect your privacy. That makes free VPN services very appealing, but you have to use a VPN service you can trust – and free VPNs don’t always fit the bill. Most reliable free VPNs are associated with known, trustworthy VPN companies. And if you’re concerned about your online privacy, it’s worth the money to subscribe to one of our recommended VPNs.
Read more: The Best VPNs for Protecting Your Privacy
Though you should always run antivirus software and keep it up to date, even with antivirus software – most of which did not flag the 911 S5 botnet VPNs – it’s important to be careful what you install on your computer. Don’t download software from websites you don’t trust and be wary of suspicious links or email attachments, any of which might install malware. This botnet took advantage of people looking to improve their online security – or possibly just get better access to streaming services – by offering a free, easy way to get online anonymously.
Scammers and cybercriminals continually look for new ways to trick us, which means we have to be vigilant for online threats. Always be cautious online and think before you download or install anything. If that file or link isn't from a trustworthy source, it could be a scam. And if an offer sounds too good to be true – like a free VPN with no strings attached – it probably is.
[Image credit: worldwide botnet concept prompted by Techlicious and generated by Midjourney]
Elizabeth Harper is a writer and editor with more than a decade of experience covering consumer technology and entertainment. In addition to writing for Techlicious, she's Editorial Director of Blizzard Watch and is published on sites all over the web, including Time, CBS, Engadget, The Daily Dot and DealNews.