Malicious PDF — malware analysis report

Static analysis result for SHA-256 764a898178815d08…

MALICIOUS

PDF

10.5 KB Created: 2009-02-19 14:45:49 -02:00 Authoring application: Writer (via OpenOffice.org 3.0)
MD5: f3258fe37cf0528807f7694c925a1981 SHA-1: 7126031e9649b1194fbb1fdd489d507f4c014d44 SHA-256: 764a898178815d08ef6a52c5d2ef112ed1df0caed649af079bc70048820fa85d
256 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1203 Exploitation for Client Execution

The PDF contains embedded JavaScript that uses eval() and String.fromCharCode() to deobfuscate and execute code. This script reconstructs and attempts to connect to the IP address '13.10.118.97', likely to download and execute a secondary payload. The critical PDF_JS_EXPLOIT_CLUSTER heuristic and ClamAV detection confirm the exploit nature of this file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 8

  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
  • ClamAV: Pdf.Exploit.Agent-35541 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35541
  • Launch action high PDF_LAUNCH
    PDF contains a /Launch action with an unresolved or extension-less target — treat as potentially dangerous
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution (matched inside decoded stream)
  • 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 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0027_000.js
4ff912584ab8a9735b26284975e9e2aea5ee7f04f1fed20150d65a5dea44af95
pdf-javascript-stream PDF /JS object 27 at offset 0x21C1 4618 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 3 eval/decoder/string-building token(s).