Malicious PDF — malware analysis report

Static analysis result for SHA-256 4dc9fc1dc7db2b0b…

MALICIOUS

PDF

2.1 KB
MD5: 962405f858931800fa665299084fae1a SHA-1: 8ca52db2d4f8cf62b96229da4fb7f3ccd1c8d7f0 SHA-256: 4dc9fc1dc7db2b0bd2962017799629fc73b230d97e6f9b9684f243264312964b
254 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript that utilizes the exportDataObject and nLaunch functions to prompt the user to save and execute the EICAR test file. This is a common technique for dropper malware to deliver a secondary payload, although in this case it is the EICAR test file itself. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 7

  • exportDataObject + nLaunch — embedded-file launch-on-open dropper critical PDF_JS_EXPORT_LAUNCH_DROPPER
    PDF JavaScript calls exportDataObject() with nLaunch set, which extracts the document's embedded file and launches it in its default application. This is a launch-on-open dropper: the embedded file is the payload. No benign workflow auto-launches an extracted PDF attachment.
  • ClamAV: Pdf.Dropper.Agent-7212321-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Dropper.Agent-7212321-0
  • 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.
  • ASCIIHexDecode filter (with exploit indicators) medium PDF_FILTER_HEX
    Hex-encoding filter present alongside exploit delivery indicators — often used to hide payload or shellcode bytes
  • 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.
  • Embedded file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
EICAR.txt
275a021bbfb6489e54d471899f7db9d1663fc695ec2fe2a2c4538aabf651fd0f
pdf-embedded-file PDF EmbeddedFile object 10 at offset 0x62C 68 bytes
Detection
ClamAV: Eicar-Test-Signature
Obfuscation or payload: unlikely
javascript_obj0008_000.js
c79586b6ce33258a4a3246f592054a0720afaa39e08ec5d2fa6c2c1d19c42b91
pdf-javascript-stream PDF /JS object 8 at offset 0x4FF 58 bytes
javascript_obj0008_001.js
a99f0aad140b19a3f2f03812ca412c6d983fae48b9344738a95bf360fb8f644c
pdf-javascript-stream PDF /JS object 8 at offset 0x4FF 56 bytes
combined_document_js_000.js
199ba6b6d17851b5ae7a01a409ca7b2ee3b1ed01f3e9b137a2572738cc785da4
deobfuscated-js combined document JavaScript streams at offset 0x4FF 115 bytes