Malicious PDF — malware analysis report

Static analysis result for SHA-256 2114b63d23e9b5cc…

MALICIOUS

PDF

13.1 KB
MD5: 5fad732b179d7a5e5c67bbeb0ac08ef6 SHA-1: 632c838cd51fd1c11d338164d8659e353460dcd0 SHA-256: 2114b63d23e9b5cc617e8ffe12e5c6e9377311c814e4e2fd7611c3e5145a35ad
186 Risk Score

Malware Insights

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

The PDF file contains obfuscated JavaScript that is designed to exploit CVE-2007-5659. The exploit stage is recovered using binary-XOR decoding and then evaluated. This technique is commonly used to download and execute a second-stage payload, although the specific payload is not recoverable from this analysis.

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
6e92b3ed7cd012837bdf825a4a25ceb04d240caa11d62e0c7c00e0c27f8749ef
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
0fd8851cb2bc39359de7e53cbb91c5648ec98e4c892ce573ed92c3c021a4862d
deobfuscated-js binary-XOR decoded JavaScript at offset 0x3F8 1294 bytes