Malicious PDF — malware analysis report

Static analysis result for SHA-256 c551163caa8f9d8c…

MALICIOUS

PDF

2.1 KB
MD5: 3f5cd83bb316334cad8d7e5966e26f73 SHA-1: a0a69ca5dbde829e8a0d6af52aeb4276081c6176 SHA-256: c551163caa8f9d8c66562829a2cee5509a37eb9ab07b8b68df3dead765cb53d6
194 Risk Score

Malware Insights

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

This PDF document contains the EICAR test file, which is a standard method for testing antivirus software. The document body explicitly instructs the user to click to save and launch the embedded EICAR.txt file. The presence of embedded JavaScript and the ML classifier further support the malicious nature of this file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 6

  • ClamAV: Heuristics.PDF.ObfuscatedNameObject critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Heuristics.PDF.ObfuscatedNameObject
  • 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