A recent analysis by HP Wolf Security underscores the escalating threat landscape associated with PDFs, with a 7% surge in PDF-related threats observed in Q4 2023 compared to Q1 of the same year. Traditionally, PDFs were commonly used for phishing attempts to extract credentials and financial details. However, the report reveals a substantial shift, indicating that 11% of the malware analyzed in Q4 utilized PDFs as a method of delivery. Notable instances include a WikiLoader campaign employing a counterfeit parcel delivery PDF to deceive users into installing Ursnif malware.
The DarkGate malware campaign is another striking example highlighted in the report. Utilizing ad tools to track victims and evade detection, cybercriminals incorporated malicious PDF attachments posing as OneDrive error messages. These attachments directed users to sponsored content on a popular ad network, enticing them to click on a link to access the promised document. Unbeknownst to the victims, this action triggered the download of files containing DarkGate malware, exploiting the widespread use of web browsers to read PDF documents.
Dr. Ian Pratt, Global Head of Security for Personal Systems at HP Inc., emphasized the sophistication of cybercriminals, employing marketing campaign tools to optimize malware delivery. He urged organizations to adhere to zero-trust principles, isolating and containing risky activities to mitigate evolving threats. The report also sheds light on the diversification of attack methods, with archives being the most popular malware delivery type, used in 30% of the analyzed incidents. Additionally, there’s a notable shift from Macros to Office exploits, with 84% of attempted intrusions involving spreadsheets seeking to exploit vulnerabilities in Office applications.
