Malicious PDF — malware analysis report

Static analysis result for SHA-256 971531d55c2d5635…

MALICIOUS

PDF

13.1 KB
MD5: 6664c75e34842a2e0de52a77487e07b0 SHA-1: ed09680415e7d9f89c2225d92b11e199a1948458 SHA-256: 971531d55c2d5635dc24b2e35f12f24abed29eba4c0bf0307aa3237f58a018c0
186 Risk Score

Malware Insights

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

The PDF file contains obfuscated JavaScript that utilizes a binary-XOR stager, a technique commonly used to hide malicious code. The critical heuristic firing for CVE-2007-5659 indicates the exploit targets a known vulnerability in Adobe Reader. The script's purpose is to decode and execute further stages, likely leading to the download of a second-stage payload.

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.
  • 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.
  • String.fromCharCode low PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically. Common in benign JavaScript libraries for codepoint manipulation, so this alone is informational; weaponised use is also caught by the dedicated fromCharCode-stage and exploit-shape rules. (matched inside decoded stream)
  • 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_obj0049_000.js
d27acdb44fbb6cab7e36bd86f481f77c1abfbb728eec2e72510a194e049f0d9f
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