Malicious PDF — malware analysis report

Static analysis result for SHA-256 f6ff0503fe23ea35…

MALICIOUS

PDF

13.3 KB
MD5: ecd9e1d59e3dc9e4a20c32dd350f03d1 SHA-1: 1c829eae65098fa224cc413bf32712a5e85030b6 SHA-256: f6ff0503fe23ea350051575e2ab4151749ee1dec5319520509f9a5069e0a865c
186 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1204.001 Malicious Link T1204.002 Malicious File

The PDF file contains obfuscated JavaScript that utilizes the `Collab.collectEmailInfo` method, indicating exploitation of CVE-2007-5659. The JavaScript is further obfuscated using binary-XOR encoding and `String.fromCharCode`, typical of a stager designed to download and execute a secondary payload. The presence of these indicators and the critical heuristic firings strongly suggest a malicious intent to compromise the user's system.

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
adb08f81abff0cd33a17099c9cb789ef05bc5661cddf378a34d1d09c81283b1b
pdf-javascript-stream PDF /JS object 49 at offset 0xA 78844 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
c1d0b40f07e054d1db24581f00b7eeec28d48f6fbe241be1cc149f33d34baa19
deobfuscated-js binary-XOR decoded JavaScript at offset 0x3F8 1318 bytes