Malicious PDF — malware analysis report

Static analysis result for SHA-256 b2bd6a6fad6c0bc2…

MALICIOUS

PDF

76.2 KB
MD5: 6e8cfcb6d0708ef3f678ebe5ab26ae57 SHA-1: 4a735c2e29ccf2a5c05ab91d71155126c7963ec6 SHA-256: b2bd6a6fad6c0bc25dc12582f362e3bf2d6049192b552619b3f99f7916924e5d
216 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that utilizes a binary XOR stager to decode and execute a second-stage payload. The critical heuristic 'CVE_2007_5659' specifically identifies the use of 'Collab.collectEmailInfo' to exploit Adobe Reader, leading to the execution of the recovered JavaScript. The script's intent is to download and execute further malicious content, leveraging the identified CVE.

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)
  • 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.
  • Suspicious extracted artifact high 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.
  • String.fromCharCode medium PDF_FROMCHARCODE
    String.fromCharCode found — used to construct payload strings dynamically
  • 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_obj0004_000.js
61ef768a3b7ab83fd030610239d624e06780e4c7c01beee67552b15e8698d412
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).