Malicious PDF — malware analysis report

Static analysis result for SHA-256 af71a817d3411298…

MALICIOUS

PDF

13.1 KB
MD5: e93ef29c3943632e23a8ae763359685c SHA-1: 5496449ca0eaf51b2d00584f87f90289ec920234 SHA-256: af71a817d3411298ac4465acbb0d26838217ce1836a01439c0587793b4152582
186 Risk Score

Malware Insights

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

The PDF file contains obfuscated JavaScript that utilizes the 'Collab.collectEmailInfo' method, a known indicator for the CVE-2007-5659 vulnerability in Adobe Reader. The JavaScript is further obfuscated using binary-XOR encoding, typical of stagers designed to download and execute additional malicious content. The presence of 'PDF_BINARY_XOR_JS_STAGER' and 'CVE_2007_5659' heuristics confirms this exploit vector. No specific family could be identified, but the technique is common for initial access.

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
45ea46ffbe887828fb26bb44e6700e82062873a0efebe96853347116b81a60a9
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
fc588205836cc70840a6be0de5822023661ff3089e15ac6d3942da47dcff2012
deobfuscated-js binary-XOR decoded JavaScript at offset 0x3F8 1294 bytes