Malicious PDF — malware analysis report

Static analysis result for SHA-256 3239ed23e8b5afc6…

MALICIOUS

PDF

125.6 KB
MD5: 26e3f3c2c3e833b2e2f74cdbaf829b68 SHA-1: b8314d23faeee2556aefadd0ef4676cf12935d8f SHA-256: 3239ed23e8b5afc6172388bc1781653946e71bf764f7375e011a7ab40d27f7f5
318 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.002 Malicious File

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` functions. The embedded JavaScript, particularly the deobfuscated `legacy_pdfkit_stage_000.js`, is designed to execute shellcode, as indicated by ClamAV detections on extracted artifacts. This points to a multi-stage attack where the PDF acts as a dropper for further malicious activity.

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
d4871b3027f1a2cdc8782a4233a70bab1023323e6fc3f1cfddfc0d861abec254
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
275f7d1acebf402ca072e8c82dd5de96528ce82ce5b301479028c641385776ff
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x98A 8394 bytes
Detection
ClamAV: Js.Exploit.Shellcode-18
Obfuscation or payload: likely
Carved artifact contains 9 eval/decoder/string-building token(s).