Malicious PDF — malware analysis report

Static analysis result for SHA-256 4037978b143342d7…

MALICIOUS

PDF

2.0 KB
MD5: 1ab4f6c1b493fa83a99d7634179ba072 SHA-1: 24d27038dbea5e9110c3deebdb43db6e608fd346 SHA-256: 4037978b143342d73809cd91b5a1cc6c28a8b6e398f8590b8499e81003e80d66
218 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that utilizes eval() and unescape() functions, indicating obfuscation. Critical heuristics identify the CVE-2007-5659 exploit (Collab.collectEmailInfo) and ClamAV detection as Pdf.Exploit.Agent-35930. The embedded JavaScript streams, particularly legacy_pdfkit_stage_000.js, are likely responsible for downloading and executing a secondary payload, a common technique for initial access.

Heuristics 7

  • 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-35930 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35930
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj111611_000.js
f23e505f155bfa9b9f356fa9fddf8d7fcafcc37fc2df3878e575e72c00c819d4
pdf-javascript-stream PDF /JS object 111611 at offset 0x6D9 697 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).
legacy_pdfkit_stage_000.js
7359904fd6ab6dbad5dd1dd0eb6762cb0df6fe97f7e4a26c183d8634f0c43a92
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x189 2652 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).