Wednesday, July 24, 2024
EHA

Hackers Embed Weaponized Word File into a PDF to Evade Detection

To avoid detection, hackers employed a new method dubbed “MalDoc in PDF” to insert a malicious Word file into a PDF file.

Despite having magic numbers and a PDF-specific file format, a file created with MalDoc in PDF may be opened in Word.

If the file includes a configured macro, running it in Word causes VBS to launch and carry out malicious operations.

The attacks that JPCERT/CC reported used the “.doc” file extension. If Windows has the “.doc” extension associated with Word, the MalDoc in the PDF-created file will open as a Word document.

Dump view of MalDoc in PDF

“The attacker adds an mht file created in Word with a macro attached after the PDF file object and saves it. The created file is recognized as a PDF file in the file signature, but it can also be opened in Word”, JPCERT/CC said in its blog.

Analysis of the Attack

Likely, PDF analysis tools like pdfid won’t be able to detect the malicious components in a file prepared using MalDoc. 

It should also be noted that this file exhibits unintended behaviors when accessed in Word; however, malicious behaviors cannot be verified when it is opened in PDF readers, etc. Since the file is recognized as a PDF file, current antivirus or sandbox tools may not detect it.

pdfid’s analysis results

“This technique does not bypass the setting that disables auto-execution in Word macros,” the JPCERT/CC team noted.

Nevertheless, if you are doing automated malware analysis using specific tools, sandboxes, etc. You should be cautious about the detection findings, as the files are recognized as PDFs.

Keep informed about the latest Cyber Security News by following us on Google NewsLinkedinTwitter, and Facebook.

Website

Latest articles

ShadowRoot Ransomware Attacking Organizations With Weaponized PDF Documents

A rudimentary ransomware targets Turkish businesses through phishing emails with ".ru" domain sender addresses....

BreachForumsV1 Database Leaked: Private messages, Emails & IP Exposed

BreachForumsV1, a notorious online platform for facilitating illegal activities, has reportedly suffered a massive...

250 Million Hamster Kombat Players Targeted Via Android And Windows Malware

Despite having simple gameplay, the new Telegram clicker game Hamster Kombat has become very...

Beware Of Malicious Python Packages That Steal Users Sensitive Data

Malicious Python packages uploaded by "dsfsdfds" to PyPI infiltrated user systems by exfiltrating sensitive...

Chinese Hackers Using Shared Framework To Create Multi-Platform Malware

Shared frameworks are often prone to hackers' abuses as they have been built into...

BlueStacks Emulator For Windows Flaw Exposes Millions Of Gamers To Attack

A significant vulnerability was discovered in BlueStacks, the world's fastest Android emulator and cloud...

Google Chrome 127 Released with a fix for 24 Security Vulnerabilities

Google has unveiled the latest version of its Chrome browser, Chrome 127, which is...
Guru baran
Guru baranhttps://gbhackers.com
Gurubaran is a co-founder of Cyber Security News and GBHackers On Security. He has 10+ years of experience as a Security Consultant, Editor, and Analyst in cybersecurity, technology, and communications.

Free Webinar

Low Rate DDoS Attack

9 of 10 sites on the AppTrana network have faced a DDoS attack in the last 30 days.
Some DDoS attacks could readily be blocked by rate-limiting, IP reputation checks and other basic mitigation methods.
More than 50% of the DDoS attacks are employing botnets to send slow DDoS attacks where millions of IPs are being employed to send one or two requests per minute..
Key takeaways include:

  • The mechanics of a low-DDoS attack
  • Fundamentals of behavioural AI and rate-limiting
  • Surgical mitigation actions to minimize false positives
  • Role of managed services in DDoS monitoring

Related Articles