Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8d83d9584bd8b86…

MALICIOUS

PDF

13.2 KB
MD5: 7f0cc7a4543af1d33042a566385a4592 SHA-1: cacfe3a231ae7f5adc77aaee5fa43c68bdba7067 SHA-256: b8d83d9584bd8b86b4883d6f7274185ae5b6f69186e43df0ba037539fc19541e
186 Risk Score

Malware Insights

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

The PDF file contains obfuscated JavaScript that exploits CVE-2007-5659, specifically targeting the Collab.collectEmailInfo function in Adobe Reader. The heuristic 'PDF_BINARY_XOR_JS_STAGER' indicates that the JavaScript is further obfuscated using binary XOR, which is then decoded to reveal the exploit stage. This suggests the primary goal is to compromise the user's system by leveraging a known vulnerability.

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
08ad7190008f8463d7fee984a224c05f002026b1f3f7e3cad22653b870aae034
pdf-javascript-stream PDF /JS object 49 at offset 0xA 78556 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
4fd1de754d5cbfb13325d7f641b85a861dd4e60a490ccd6733c27a708ccefc92
deobfuscated-js binary-XOR decoded JavaScript at offset 0x3F8 1312 bytes