Malicious PDF — malware analysis report

Static analysis result for SHA-256 f384fad2bd230a84…

MALICIOUS

PDF

13.1 KB
MD5: 548325b00851bb166deb39a725b9b6fd SHA-1: 6287b3ba80c5c9429f419f162b3d8934f68203ca SHA-256: f384fad2bd230a84d4ed1f665db7dc2267d8e3b0b0b490a52de6c4d11f663fc7
216 Risk Score

Malware Insights

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

The PDF file contains obfuscated JavaScript that utilizes the 'Collab.collectEmailInfo' method, indicating exploitation of CVE-2007-5659. The JavaScript is further obfuscated using binary-XOR encoding and string concatenation, typical of stagers designed to download and execute additional malicious content. The presence of extracted JavaScript files and the critical heuristic firings strongly suggest this is a malicious PDF dropper.

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: Heuristics.PDF.ObfuscatedNameObject critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Heuristics.PDF.ObfuscatedNameObject
  • Binary-XOR JavaScript stager high PDF_BINARY_XOR_JS_STAGER
    PDF JavaScript stores viewer-version payload branches as long binary digit strings, XORs each bit pair, converts 8-bit chunks with String.fromCharCode, and evals the recovered exploit stage.
  • String.fromCharCode medium PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically (matched inside decoded stream)
  • Suspicious extracted artifact medium 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.
  • 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.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0049_000.js
a05471f56837d5dc5393cbd7a220892a74222d89a0364a4a3558a359f5e4586a
pdf-javascript-stream PDF /JS object 49 at offset 0xA 77692 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s). Carved artifact contains 6 long base64-like blob(s).
binary_xor_stage_000.js
55444ec2f8d5d15aa2c4ea19727dc2d8337e9d773a0cd6a453f74d50abb16710
deobfuscated-js binary-XOR decoded JavaScript at offset 0x3F8 1294 bytes