Malicious PDF — malware analysis report

Static analysis result for SHA-256 9804b1c74665fb7e…

MALICIOUS

PDF

17.7 KB Created: 2009-07-24 18:54:15 Authoring application: bTOAaGb (via BzLlCR1x2)
MD5: e0dc79ce25d2128e0865187bc9989a9c SHA-1: 120d820b71b3fb97f8b5416c59f71e10f81e7df7 SHA-256: 9804b1c74665fb7ecb4e15bcb7d4ad5d079a4408ee048328c4421119e3d3878d
338 Risk Score

Malware Insights

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

The PDF file contains obfuscated JavaScript that leverages multiple Adobe Reader vulnerabilities, specifically CVE-2007-5659 (Collab.collectEmailInfo) and CVE-2008-2992 (util.printf). The JavaScript is heavily obfuscated and appears to be a multi-stage exploit kit designed to download and execute a second-stage payload. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 9

  • 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)
  • Multi-CVE Adobe Reader JavaScript exploit kit critical PDF_ADOBE_READER_MULTI_CVE_JS_KIT
    One recovered JavaScript stage contains multiple version-gated Adobe Reader exploit branches. This is stronger evidence than independent API keywords: the PDF is selecting old Reader vulnerabilities by viewer version and running heap-sprayed Acrobat JavaScript exploit paths.
  • ClamAV: Js.Trojan.Obfus-48 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Js.Trojan.Obfus-48
  • 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.
  • 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_obj0007_000.js
8726f747d4fc2050624d46161130a64f1cb48e942f5ef4534455c67f6ac6a058
pdf-javascript-stream PDF /JS object 7 at offset 0x243 16748 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 7 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
custom_b64_stage_000.js
aa6119d038aaa5da5cda642c66238e506612db4887ed79090dd2a16be034474f
deobfuscated-js custom Base64 decoded JavaScript layer 3 (PDF /JS object 7) at offset 0x1235 4600 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).