Malicious PDF — malware analysis report

Static analysis result for SHA-256 926742bb0a06ca7e…

MALICIOUS

PDF

13.1 KB
MD5: fd9300e8e78db5a294b2ac20d9b78de0 SHA-1: 5a41d059c719ab516424a0949a846eac1d5e76f8 SHA-256: 926742bb0a06ca7eeaf7945d3f27136ded9a3ad5c0cef7d924fda6b27f8a2559
186 Risk Score

Malware Insights

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

This PDF file contains obfuscated JavaScript that utilizes a binary-XOR stager to decode and execute a second-stage payload. The critical heuristic 'CVE_2007_5659: Collab.collectEmailInfo' indicates the exploitation of a known vulnerability in Adobe Reader. The JavaScript is heavily obfuscated, but the stager is designed to recover and execute exploit code, likely leading to further malware infection.

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
f9eb751dc7ea80b910410752a17937f04fd2e760eb39cf47b0426fa249112207
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