PDF files are a popular way of sharing documents online, but they can also pose a serious security risk. In a recent statement, Google warned that Russian state-sponsored hackers are sending encrypted PDFs to trick victims into running a decryption tool that’s malware. In this article, we explain how hackers use PDF files to spread malware. We’ll also summarise what you can do to guard against falling victim to their dirty tricks.
Why are PDF files dangerous?
Many people think that PDF files are safer than Word documents because they are harder to modify and don’t have macro viruses. However, this is not true. PDF files can contain embedded links, images, scripts, and other malicious elements that can execute when you open the file. These elements can redirect you to harmful websites, download malware to your computer, or exploit vulnerabilities in your system.
Hackers can create malicious PDF files using toolkits that are easily available on the internet. Some of these toolkits are even used by white hat hackers for testing purposes, but they can also be abused by cybercriminals. Some of the malicious PDF files have signatures that antivirus software can detect and block, but others are more sophisticated and can evade detection.
How do hackers trick you into opening malicious PDF files?
Hackers use various social engineering techniques to lure you into opening their malicious PDF files. They may send you an email that looks like it comes from a legitimate source, such as a bank, a government agency, or a colleague. The email may contain a PDF file as an attachment or a link to download it. The PDF file may have a convincing name, such as an invoice, a report, or a receipt.
Alternatively, hackers may use encrypted PDF files as bait. They may send you an encrypted PDF file that you cannot open and then follow up with another email that contains a link to a supposed decryption tool. The decryption tool is malware that infects your computer when you run it.
How can you prevent malicious PDF files from harming you?
The best way to protect yourself from malicious PDF files is to be cautious and vigilant. Here are some tips to follow:
- Do not open PDF files from unknown or suspicious sources. If you receive an unexpected or unsolicited email with a PDF file attached or linked, delete it or mark it as spam.
- Do not open encrypted PDF files unless you are sure of their origin and authenticity. If someone sends you an encrypted PDF file and then asks you to download a decryption tool, do not do it. It is likely a scam.
- Use reputable antivirus software and keep it updated. Antivirus software can help you detect and remove malware from your computer. However, antivirus software is not foolproof and may not catch all malicious PDF files. Therefore, you should also use common sense and follow the other tips.
- Use a secure PDF reader and disable unnecessary features. Some PDF readers have features that can make them vulnerable to attacks, such as JavaScript, plugins, or automatic updates. You should disable these features or use a PDF reader that does not have them. You should also update your PDF reader regularly to fix any security issues.
- Scan any PDF file before opening it. You can use online tools or your antivirus software to scan any PDF file for malware before opening it. This can help you identify potential threats and avoid them.
By following these tips, you can reduce the risk of falling victim to malicious PDF files and keep your data and devices safe. Are you concerned about continually evolving cyber threats to your business? Contact Modern Networks today to discuss how we can help you improve your security posture.
Call us at 01462 426500 or email us at info@modern-networks.co.uk. Alternatively, visit our cybersecurity-as-a-service webpage to learn more.
