Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8167ef1236a1a34…

MALICIOUS

PDF

9.3 KB
MD5: 6b71b406858e2dbc97d319f49528e155 SHA-1: 0bf1cefd85e39ad2d4d1d667bc6e05eba020d07e SHA-256: c8167ef1236a1a34decb8182e9be799ebf97bd0460c9f6ec48e971d2858050c7
178 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that is heavily obfuscated and utilizes the unescape() function, indicating an attempt to hide malicious code. The critical heuristic firing for CVE-2007-5659, specifically the Collab.collectEmailInfo method, confirms the exploitation of a known PDF vulnerability. The ClamAV detection further supports the malicious nature of the file. The embedded JavaScript streams are likely responsible for downloading and executing a second-stage payload.

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
7737c313ab3f13a7d0119c5d6312852cc3795a9b5a1a847e32d890f64cac1b62
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2FE 11875 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
063bb48d96cce0e4f5b739d1225683fd2146ec249fc8ee46a34e30b640b5088a
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2FE 4937 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).