Malicious PDF — malware analysis report

Static analysis result for SHA-256 51195395e9470dee…

MALICIOUS

PDF

631.5 KB First seen: 2026-05-07
MD5: 051e14f84eebd9106eedd4a806081e75 SHA-1: 2699a025021e34a594e64b76eb9965749fb90294 SHA-256: 51195395e9470dee9b5014e8346b142afcbabb40a9f22e37c7505e7b883705d0
156 Risk Score

🔏 Digital signature Signed

A signature covers the whole signed byte range — PDF JavaScript is never signed on its own — and does not by itself mean the document is safe.

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File T1059.001 PowerShell

The PDF file contains embedded JavaScript and is flagged as related to CVE-2023-26369, indicating an exploit attempt. The embedded JavaScript streams, particularly 'stream_002_off00000511.js', are highly suspicious and likely responsible for executing the malicious payload. The presence of 'String.fromCharCode' suggests obfuscation techniques were used within the script.

Machine Learning

  • Nyx PDF Classifier suspicious score 0.2668

Heuristics 8

  • TrueType bitmap font + active content — CVE-2023-26369 related high CVE related PDF_CVE_2023_26369_RELATED
    PDF embeds a TrueType font with bitmap tables (EBDT/sbix/CBDT) alongside exploit delivery indicators — CVE-2023-26369 exploits the sfac_GetSbitBitmap function in Adobe's libCoolType for arbitrary code execution. This CVE was actively exploited in the wild, but this rule does not validate the malformed EBLC/EBDT primitive.
  • JavaScript action low 2 related findings PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules. (matched inside decoded stream)
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
    Matched line in script
       if (randomNumber < NUMBERS) {
    code += String.fromCharCode(randomNumber + NUMBER_POS);
   } else {
  • 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. (matched inside decoded stream)
  • Embedded script payload in PDF stream medium PDF_EMBEDDED_SCRIPT_PAYLOAD
    PDF stream bytes contain an HTML/XFA <script> tag without accompanying Windows shell-execution primitives — common in accessible XFA forms but worth surfacing for analyst review.
  • XFA form low PDF_XFA
    PDF uses XML Forms Architecture — can contain script logic
  • 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.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://www.monotype.comMonotype In PDF document text
    • http://ocsp.verisign.com0In PDF document text
    • http://www.adobe.com/go/reader_downloadIn PDF document text
    • http://www.adobe.com/go/acrreaderIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/xfa/promoted-desc/In PDF document text
    • http://www.xfa.org/schema/xfa-template/3.0/Referenced by PDF JavaScript
    • http://www.w3.org/1999/xhtmlReferenced by PDF JavaScript
    • http://www.xfa.org/schema/xfa-data/1.0/Referenced by PDF JavaScript
    • http://www.xfa.org/schema/xfa-template/2.8/Referenced by PDF JavaScript
    • http://cgi.adobe.com/special/acrobat/updateReferenced by PDF JavaScript
    • http://www.xfa.org/schema/xci/3.0/In PDF document text
    • http://www.xfa.org/schema/xfa-template/2.8/\In PDF document text
    • http://www.w3.org/1999/xhtml\In PDF document text
    • http://www.xfa.org/schema/xfa-data/1.0/\In PDF document text
    • http://www.xfa.org/schema/xfa-locale-set/2.7/In PDF document text
    • http://www.xfa.org/schema/xfa-connection-set/2.8/In PDF document text
    • http://www.bde.es/IntDescExcIn PDF document text
    • http://ns.adobe.com/data-description/In PDF document text
    • https://www.verisign.com/rpaIn PDF document text
    • http://ocsp.verisign.com/ocsp/status0In PDF document text
    • https://www.verisign.com/rpa0In PDF document text
    • http://crl.microsoft.com/pki/crl/products/CodeSignPCA.crl0In PDF document text
    • http://www.microsoft.com/typographyIn PDF document text
    • http://www.monotype.com/html/mtname/ms_arial.htmlhttp://www.monotype.com/html/mtname/ms_welcome.htmlhttp://www.monotype.com/html/type/license.htmlIn PDF document text
    • http://crl.verisign.com/tss-ca.crl0In PDF document text
    • http://crl.verisign.com/ThawteTimestampingCA.crl0In PDF document text
    • http://logo.verisign.com/vslogo.gif0In PDF document text
    • http://csc3-2010-crl.verisign.com/CSC3-2010.crl0DIn PDF document text
    • http://csc3-2010-aia.verisign.com/CSC3-2010.cer0In PDF document text
    • https://www.verisign.com/cps0*In PDF document text
    • http://logo.verisign.com/vslogo.gif04In PDF document text
    • http://crl.verisign.com/pca3-g5.crl04In PDF document text
    • http://www.adobe.com/typehttp://www.adobe.com/type/legal.htmlIn PDF document text

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 11

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_001_off00000121.js decompressed-pdf-stream PDF FlateDecoded stream at offset 0x121 2568 bytes
SHA-256: dce7f7ebf6612f0dbc0daf4a7468618c8c43cb1f9d11990a67d193ae6773fda0
stream_002_off00000511.js decompressed-pdf-stream PDF FlateDecoded stream at offset 0x511 323976 bytes
SHA-256: d0474e9e899b32fa82ad0af875d29297823535a0fc0462d5cf9d248952d37138
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 eval/decoder/string-building token(s). Carved artifact contains 2 long base64-like blob(s).
stream_003_off000164f1.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x164F1 2893 bytes
SHA-256: 984e33597cee6a139b4eb9668deb8ae3fd023cb2f29b1dac2e77dd6be0d9a93d
stream_005_off00016a94.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x16A94 332 bytes
SHA-256: c33fb1ac7109889c7c4b9c859e851de7c5d7b479cf91705d24a8792a803323cf
stream_006_off00016bbc.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x16BBC 5521 bytes
SHA-256: e0276814666cb19b977bcc644bf104853ec7e618e6c32fe265317df225f1ad84
stream_010_off0006646f.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x6646F 367087 bytes
SHA-256: b8e2518b116c26bab0e9f8c1672daf405dedad561157502b657e9005be2029aa
stream_012_off0009acd1.js decompressed-pdf-stream PDF FlateDecoded stream at offset 0x9ACD1 1363 bytes
SHA-256: 529357503ec67b623d2a12816cdeea62bd639f2b4ff4e568b01c96cc3f5bfc6f
stream_013_off0009aeaf.js decompressed-pdf-stream PDF FlateDecoded stream at offset 0x9AEAF 902 bytes
SHA-256: e985b5df65c8c3cf732a9074b575fbc594c1c7f0bccc0994182ec7e5c0f7308a
objstm_0013_00.bin pdf-objstm-decoded PDF /ObjStm 13 0 obj (inflated) 14639 bytes
SHA-256: 57b13bfa12ee6c264fd8fa414b8686696bc052252f08d22895b85f753c0d3566
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 long base64-like blob(s).
font_00_sfnt_off00017020.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17020 96552 bytes
SHA-256: bb2941ec4287d456b111082246b159a552fabcbd95c93efecdf11c9146f57370
font_01_sfnt_off00027472.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x27472 98046 bytes
SHA-256: b8a01f1bf52ef962d6ee77e0a9299704d38617565ea12f2a6dc7a39cdb0062eb

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