Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a850f6390fba141…

MALICIOUS

PDF

3.4 KB Created: 2008-31-20 53:85:00 Authoring application: Scribus 1.3.3.12 (via Scribus PDF Library 1.3.3.12)
MD5: 05741fc716dfbf4756bda1ba69fb8829 SHA-1: 4bdfccb34207959916226d83944875bf4f1f226e SHA-256: 9a850f6390fba141b80a32bc57fe039e0bef00d068ee0653127ac9c26bbe3291
346 Risk Score

Malware Insights

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

The PDF document contains embedded JavaScript that utilizes eval() and String.fromCharCode() functions, indicative of obfuscation. Critical heuristics identify exploitation of CVE-2007-5659 (Collab.collectEmailInfo) and CVE-2008-2992 (util.printf). These vulnerabilities are leveraged to execute deobfuscated JavaScript, which is designed to download and execute a secondary payload. ClamAV detections further confirm the malicious nature of the file and its extracted artifacts.

Heuristics 10

  • 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-36167 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Agent-36167
  • 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.
  • OpenAction trigger high PDF_OPENACTION
    PDF has an /OpenAction — code runs automatically when opened
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • 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.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • 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_obj0013_001.js
f0330436a4937c80702bbbbd976d9195779ba9296e3e533abce0cfbae0880d84
pdf-javascript-stream PDF /JS object 13 at offset 0x3D7 11431 bytes
Detection
ClamAV: Win.Trojan.Agent-36167
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).
numeric_charcode_stage_000.js
c18efd0c7a1edbb705af9e5c8eda1c329ac93fb743885848961c040d0a315fa5
deobfuscated-js numeric char-code string decoded JavaScript at offset 0x437 3324 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).