Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b679f236ece2e41…

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: d4f84d9711c10c0ac8f995fbe4586f1c SHA-1: a37d910fbc6a89300ed417e5f7ad4c93a61e67f4 SHA-256: 8b679f236ece2e417a9923355eaf072d55211dea2cd3e2d7b91e8a40a84f6f2c
346 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that is obfuscated using character codes and the eval() function. This script exploits known vulnerabilities (CVE-2007-5659 and CVE-2008-2992) in Adobe Reader to achieve arbitrary code execution. The primary intent appears to be the download and execution of a second-stage payload, as indicated by ClamAV detections of Win.Trojan.Agent-36167 on the original file and an extracted artifact.

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
a26187f6744e76d47fde97c639b3f5a232faebbf3d6cf311f728bc8d35624b66
pdf-javascript-stream PDF /JS object 13 at offset 0x3D7 11469 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
845447adf5adbec91e633d89794696a97c9afe04d8ab37c5c09602a8a5fe6e70
deobfuscated-js numeric char-code string decoded JavaScript at offset 0x437 3336 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).