Malicious PDF — malware analysis report

Static analysis result for SHA-256 2aaa5121736cf88e…

MALICIOUS

PDF

76.2 KB
MD5: f6d659853bde1f7691e398389bd6f06e SHA-1: af9a8e11da043cad55a072fd7ba5575551e190c6 SHA-256: 2aaa5121736cf88ef5a7e5d85db2abc33f36e316f62b1eb6bda3265efb3a76ea
226 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link T1071.001 Web Protocols

The PDF file contains obfuscated JavaScript that utilizes a binary-XOR stager. This stager decodes embedded strings and exploits CVE-2007-5659 via the Collab.collectEmailInfo method. The exploit stage is then evaluated, indicating the file's purpose is to download and execute a secondary payload. The ClamAV detection confirms its malicious nature.

Heuristics 8

  • 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.Dropper.Agent-7243073-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Dropper.Agent-7243073-0
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution
  • 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.
  • 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_obj0004_000.js
dabee3d283d6a00cd8b3dcb7c6c3050e9a700c1f1116e46630b68db419653f5f
pdf-javascript-stream PDF /JS object 4 at offset 0xC0 77722 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s). Carved artifact contains 6 long base64-like blob(s).
binary_xor_stage_000.js
9f2e93d9307bbfd4bba986d31eaac349e5fa7226a29722c25c7db7004b08045c
deobfuscated-js binary-XOR decoded JavaScript at offset 0x3D7 1273 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).