Watch Out for Free Online File Converters That Are Actually Malware

Converting a .pdf to a .docx and back again may seem like a quick and easy thing you can do online for free—but that doesn't mean it's safe. A new notice from the FBI Denver Field Office warns that some online document converters are also loading malware onto unsuspecting users' computers, giving bad actors access to your device and your data.

The tools may also scrape files submitted for conversion for sensitive information, such as Social Security numbers, birthdates, email addresses, passwords or tokens to bypass multi-factor authentication, banking information, and cryptocurrency seed phrases and wallet addresses.

How to spot malicious file converters

This scheme may be easy to miss, as the malicious file converters will do what they advertise, such as converting a .docx to a .pdf or joining multiple files into one. However, the file you download may contain hidden ransomware, adware, or riskware that exposes your computer to attackers. You may also be prompted to download a conversion tool (that is actually malware) to your device or install a malicious browser extension.

According to a Malwarebytes Labs report on the scam, the following domains have been found to contain malware:

• Imageconvertors[.]com (Phishing)

• convertitoremp3[.]it (Riskware)

• convertisseurs-pdf[.]com (Riskware)

• convertscloud[.]com (Phishing)

• convertix-api[.]xyz (Trojan)

• convertallfiles[.]com (Adware)

• freejpgtopdfconverter[.]com (Riskware)

• primeconvertapp[.]com (Riskware)

• 9convert[.]com (Riskware)

• Convertpro[.]org (Riskware)

While these are known scams, that doesn't mean there aren't other free, malware-containing file converters out there waiting to infect your device. The best thing you can do is avoid these tools entirely and utilize trusted software instead. But if you suspect you've been exposed, start by taking basic steps to secure your identity, including changing passwords using a clean, trusted device, and running an anti-malware program to catch any threats.

How to convert files safely

When you need to quickly convert from one document type to another, you may be tempted to google "free file converter" and click on whatever comes up—but don't.

Instead, start with the software or applications you have that can open the file, and check if you can export or save it in a different format (look under File > Export or File > Save As). Microsoft Office and many PDF editors have this functionality, or you can use Adobe's free tools to convert to and from a PDF, as well as a handful of other document converters available for free.

Remember that when you convert files, you may lose some formatting in the process.