Malicious PDF — malware analysis report

Static analysis result for SHA-256 87acfcf6b5fbf990…

MALICIOUS

PDF

7.8 KB Created: 2008-31-20 53:85:00 Authoring application: Scribus 1.3.3.12 (via Scribus PDF Library 1.3.3.12)
MD5: 2aba41b5ce981dcf4a61b7cbc7358180 SHA-1: bfb96f4de420d55a578ef2c8b86d7fcbe727a765 SHA-256: 87acfcf6b5fbf99095cf7d5df83fa69612137b73e78578d00762a108043b1af1
270 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The sample is a malicious PDF that contains embedded JavaScript. This script utilizes eval() calls and string concatenation to obfuscate its true purpose, which is to download and execute a second-stage payload. The embedded URLs are likely related to the distribution or command and control infrastructure of this malware. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

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-35587 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-35587
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • eval() call high PDF_EVAL
    eval() found — commonly used for obfuscated exploit execution
  • 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.
  • 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.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://phpnet.us/byet300x250.php
    • http://ad.foxnetworks.com/st?ad_type=pop&ad_size=0x0&section=204717&banned_pop_types=28&pop_times=5&pop_frequency=86400

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0013_001.js
9433c73853b395abd4a323f8ad315f584feada2b4444ae207d29ca96c784451d
pdf-javascript-stream PDF /JS object 13 at offset 0x3D6 5715 bytes
Detection
ClamAV: Pdf.Exploit.Agent-35587
Obfuscation or payload: likely
Carved artifact contains 5 eval/decoder/string-building token(s).