Malicious PDF — malware analysis report

Static analysis result for SHA-256 3e66db2dd9c0b519…

MALICIOUS

PDF

12.0 KB
MD5: 7d9e3e4f0156b312d508fbf33727191e SHA-1: 22d529f728242c951eee86768b06f19d6be6ef33 SHA-256: 3e66db2dd9c0b519b86e9e23d26c195cef23244ee8fe9fe930836b9b582ec906
198 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link T1071.001 Web Protocols

The PDF file contains obfuscated JavaScript, triggered by the CVE-2007-5659 vulnerability using the 'Collab.collectEmailInfo' function. Static analysis recovered two deobfuscated JavaScript files, 'legacy_pdfkit_stage_000.js' and 'legacy_pdfkit_stage_001.js', which are indicative of a multi-stage attack. The primary function of the embedded scripts appears to be downloading and executing further malicious content, consistent with a downloader or initial access exploit.

Heuristics 6

  • 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)
  • Annotation subject percent-decoding eval stager critical PDF_ANNOT_SUBJECT_MARKER_EVAL_STAGER
    OpenAction JavaScript forces annotation enumeration, reads an annotation /Subject payload with getAnnots(), rewrites marker bytes into percent escapes, decodes it with unescape(), and dispatches it through eval. This is a high-confidence exploit-kit staging pattern. It is intentionally not mapped to CVE-2009-1492 unless getAnnots() itself carries the crafted integer or long argument shape for that vulnerability.
  • ClamAV: Heuristics.PDF.ObfuscatedNameObject critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Heuristics.PDF.ObfuscatedNameObject
  • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0007_000.js
6f60a1053baafdc578f85eae84a2dc6d16775fbd66240d82cbfb7b4f4ff4e90a
pdf-javascript-stream PDF /JS object 7 at offset 0x19D 295 bytes
legacy_pdfkit_stage_000.js
54a69749873e7531758cab0462d8b2e734330274bf730161822c5a8a0cf3f475
deobfuscated-js z-percent hex-pair decoded JavaScript at offset 0x2E9 5057 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).
legacy_pdfkit_stage_001.js
62a0a70f4393700ff5944c9d4222b3b460d5e5d42f0f83a9c775f24a2e46cdbd
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2E9 12035 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).