Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c23ed88c4574dff…

MALICIOUS

PDF

125.9 KB
MD5: 6034f2796f9d77da3c0960729463fc2f SHA-1: f80dc9443c917e6a71c065500463902d12ee363d SHA-256: 3c23ed88c4574dff722b7eede4b2838650f4b538b2fe3ee687835f612d401dc6
318 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link

The PDF file contains embedded JavaScript that leverages multiple known vulnerabilities (CVE-2009-0927, CVE-2007-5659, CVE-2008-2992) through the use of `Collab.getIcon`, `Collab.collectEmailInfo`, and `util.printf`. The deobfuscated JavaScript, named `legacy_pdfkit_stage_000.js`, likely serves as a downloader for a secondary stage. ClamAV detections on both the original PDF and the extracted JavaScript further confirm its malicious nature.

Heuristics 8

  • Collab.getIcon — CVE-2009-0927 critical CVE exact CVE_2009_0927
    PDF JavaScript calls Collab.getIcon — CVE-2009-0927 is a stack buffer overflow in Adobe Reader triggered by Collab.getIcon() with a crafted argument. Allows arbitrary code execution. (identified after JavaScript deobfuscation)
  • Collab.collectEmailInfo — CVE-2007-5659 critical CVE exact CVE_2007_5659
    PDF JavaScript calls Collab.collectEmailInfo — CVE-2007-5659 is a buffer overflow in Adobe Reader triggered by a long argument or heap-sprayed message field passed to Collab.collectEmailInfo(). Part of a series of Acrobat JS API exploits. (identified after JavaScript deobfuscation)
  • util.printf — CVE-2008-2992 critical CVE exact CVE_2008_2992
    PDF JavaScript calls util.printf() — CVE-2008-2992 is a stack buffer overflow in Adobe Reader triggered by a long format-specifier argument. Widely exploited in the wild after disclosure. (identified after JavaScript deobfuscation)
  • ClamAV: Win.Trojan.Agent-36169 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Agent-36169
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0008_000.js
529c69122ce28878e3eff842109927685bb2074396f30bdbb8e35fd65bd1f55e
pdf-javascript-stream PDF /JS object 8 at offset 0x1E7 1903 bytes
Detection
ClamAV: Win.Trojan.Agent-36169
Obfuscation or payload: unlikely
legacy_pdfkit_stage_000.js
807b4e5e49aaa22a8138c68a42ef80898d9b395f614d86a5554778e0b92b373a
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x98A 8412 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 9 eval/decoder/string-building token(s).