Malicious PDF — malware analysis report

Static analysis result for SHA-256 de816b0e96861cf3…

MALICIOUS

PDF

9.2 KB
MD5: 7c23db9e543dba4de2cd1dd29254ef0f SHA-1: 360b92157c75042fc5cb7bf60394ebe478da0369 SHA-256: de816b0e96861cf3a6da733f5ad91620cb605195232a17bf45ab7e476bcc2a37
208 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that is obfuscated and utilizes the unescape() function, indicating malicious intent. The critical heuristic CVE_2007_5659 specifically points to the exploitation of this vulnerability via the Collab.collectEmailInfo method. The embedded JavaScript is likely responsible for downloading and executing a second-stage payload. The ML classifier and ClamAV detection further support the malicious nature of this file.

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
6d244c073d4c7eae078a8d784251da74e531f736f0f563eb19481b51e90f9cbf
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2FE 11645 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
2eeaccaa697241b14a420d28f3529d56a32c7abc29557fbf3eb241f780cf5544
deobfuscated-js repeated-marker hex decoded JavaScript at offset 0x2FE 4929 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).