Malicious PDF / .PHP — malware analysis report

Static analysis result for SHA-256 668c805035633279…

MALICIOUS

PDF / .PHP

37.0 KB Created: 2010-04-19 00:00:35 +04:00 Authoring application: TCPDF (via TCPDF 4.8.032 (http://www.tcpdf.org))
MD5: f27fbc0bffbb4bf2b4d3f724c724b994 SHA-1: b6604efb9004bc36c84608d1e9b16ff15ffe12a0 SHA-256: 668c8050356332796d66c2cba20052eaa4f1090978e3fdad1d00abc94f803029
114 Risk Score

Malware Insights

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

The PDF file contains embedded JavaScript that is obfuscated but appears to construct a string and then execute it using `eval()`. This JavaScript is likely responsible for downloading and executing a secondary payload, as indicated by the ML classifier and ClamAV detection. The specific string constructed and executed by the JavaScript is not fully reconstructible due to obfuscation, but the `eval()` call itself is a critical indicator of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 4

  • ClamAV: Pdf.Exploit.Agent-23690 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Exploit.Agent-23690
  • 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.
  • Optional Content Group with action trigger low PDF_OPTIONAL_CONTENT
    Optional Content Group (layer) co-occurs with an action trigger — content can be selectively hidden from viewers or scanners while the action still fires on open

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0010_000.js
6379efcb781d596b803b854413c710f7c9627940da7f8339d7341efbf646cb83
pdf-javascript-stream PDF /JS object 10 at offset 0x89C0 1344 bytes