Malicious PDF — malware analysis report

Static analysis result for SHA-256 21cdd37091ad5dbf…

MALICIOUS

PDF

2.1 KB
MD5: dfd07edbe8d061f3f89cc88d2af85915 SHA-1: 98fcae2b05586a567eca70604821e5ad0363b4c0 SHA-256: 21cdd37091ad5dbf33110c49a594a7c61a7cc432739a51d4b555bc4b11f13dd7
194 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1566.001 Spearphishing Attachment

This PDF document contains the EICAR test string within its body and also embeds the EICAR test file. The document prompts the user to click to save and launch the embedded EICAR test file. This behavior is indicative of a dropper or a test case designed to trigger anti-virus software. No JavaScript actions were directly executed, but the presence of embedded files and the ML classifier's high confidence score support the malicious verdict.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 6

  • ClamAV: Pdf.Dropper.Agent-7238576-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Dropper.Agent-7238576-0
  • 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 3

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