Malicious PDF — malware analysis report

Static analysis result for SHA-256 e984fec7f09371e5…

MALICIOUS

PDF

9.3 KB
MD5: c5d8487fd1e65c6755cdfe9e2822e735 SHA-1: d11589c63a2d5a26ad56f23a89b6cd61a93b8ae7 SHA-256: e984fec7f09371e503ec2f491948e380d2324475a3a6bd66839dbcaeedbd0027
208 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 JavaScript/JScript T1204.001 Malicious Link/URL T1071.001 Web Protocols

The PDF contains embedded JavaScript that leverages the CVE-2007-5659 vulnerability via the Collab.collectEmailInfo method. The JavaScript is heavily obfuscated, but the presence of unescape() calls and the ML classifier's high confidence score indicate malicious intent. The primary function appears to be the execution of further malicious code, likely a downloader for a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

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)
  • ClamAV: Pdf.Exploit.Agent-35905 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35905
  • unescape() call high PDF_UNESCAPE
    unescape() found — often used to decode shellcode in PDF JS exploits (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.
  • 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
d8a6b4ad1abf04d0c4a4f89535cfb57f7312edef25c443f4e844c8ec9d0929dd
pdf-javascript-stream PDF /JS object 7 at offset 0x19B 352 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
35daa5e9ac1722459f97ea95f1d2913bbc534f4e51b67ae59597dd5e60fb9bc1
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2FE 11809 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 1 long base64-like blob(s).
legacy_pdfkit_stage_001.js
56fdd52470f383a0ca8b40063634a6df8acee414ab0f85db1cf0ed8f33dc2cfc
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2FE 4950 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).