Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a4b31cde3a04280…

MALICIOUS

PDF

95.0 KB Created: 2021-09-06 23:31:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 41f83ea15f4ed6c1036d876faafc49c1 SHA-1: 8d931385fd44940d50a58e2c43eb77400d05970b SHA-256: 8a4b31cde3a04280f47fc4a2625671402e79f4b9fbaf330f629a13224c19a0a7
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV. It contains numerous external links, many pointing to compromised websites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this. The document body is heavily obfuscated and unreadable, indicating an attempt to hide its true purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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 https://drafthe.ru/uplcv?utm_term=seladora+de+sacos+plasticos+manual PDF link annotation
    • https://morethancleaningservices.com/wp-content/plugins/super-forms/uploads/php/files/b483aca3b5fa263198bd13c4833fca12/83518499538.pdfIn PDF document text
    • http://reunionclass.com/clients/7469/File/70786748255.pdfIn PDF document text
    • http://adabaskimerkezi.com/upload/file/xadafumivizerovam.pdfIn PDF document text
    • http://nappsa.org/userfiles/file/netebum.pdfIn PDF document text
    • https://olivierdaulte.com/ckfinder/userfiles/files/jimujonuwe.pdfIn PDF document text
    • https://nhachoxebus.com/upload/fck/file/57819061689.pdfIn PDF document text
    • http://dgjst.com/upfile/file/guresorofimivovajo.pdfIn PDF document text
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/58c33af0506b740a1729ac85972a5bb7/tosawined.pdfIn PDF document text
    • http://hykylalumni.org/userfiles/janajidum.pdfIn PDF document text
    • http://schokozentrale.de/idata/rabapib.pdfIn PDF document text
    • https://lightsourceindiana.com/wp-content/plugins/super-forms/uploads/php/files/c8fe9558dafafc6b4658d907d9c9816b/mafuli.pdfIn PDF document text
    • https://gresathouse.com/wp-content/plugins/super-forms/uploads/php/files/f19ee862eaa6b3c9dc80ef2a19f2bc06/jufisoratijaxujikelo.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5f4ce9e84c---65238115406.pdfIn PDF document text
    • http://xn--9n2bn9mz3aba29g44r4o0a.kr/fckeditor/userfiles/image/67838134947.pdfIn PDF document text
    • http://2446665a.ru/ckfinder/userfiles/files/varulalusu.pdfIn PDF document text
    • http://netinflux.net/userfiles/file/4798992009.pdfIn PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/c13bf4c02d87608d8b441c1af016bc46/fataforefi.pdfIn PDF document text
    • http://pune-india.info/userfiles/file/wefixarijapawetexasud.pdfIn PDF document text
    • http://hotelborgodeipoeti.com/userfiles/files/47427156191.pdfIn PDF document text
    • https://network-italia.it/file/71840606542.pdfIn PDF document text
    • http://tantex.org/tantex/tantexuserfiles/file/purigerugisitevalamesib.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010eed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EED 17772 bytes
SHA-256: c4d6a4b6df697cc441a319fc0d6917f9f75765c3ba640d636f24496924ffefd6
font_01_sfnt_off00013c02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C02 10848 bytes
SHA-256: 1079a38b18648a5205b50c7a272e9583dbe08288b5efe9e30d7fe812957a0bd2
font_02_sfnt_off000154fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x154FD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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