Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4bac9042eb57d6c…

MALICIOUS

PDF

93.2 KB Created: 2021-07-27 06:08:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: ff86f39d90c7167fdfd696332871a27e SHA-1: 932eabe77a77911256f36629a5b8ef135acfa9dc SHA-256: a4bac9042eb57d6c36d8f4140dfb940235e29c441e7e17307f7385117f024135
176 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The document contains a link farm pointing to numerous compromised websites, likely for SEO manipulation or to host malicious content. The presence of multiple PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics indicates a pattern of leveraging compromised web infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://smallislandcurry.com/wp-content/plugins/super-forms/uploads/php/files/adf51254d1126c0b9e3a7dd286b77665/bezurenetewumijosotonik.pdf In PDF document text
    • https://www.uniqueartzz.com/wp-content/plugins/super-forms/uploads/php/files/svdko07uq3far410i4tr3de2ds/71908807551.pdfIn PDF document text
    • https://sf-tfi-pgu.uz/wp-content/plugins/super-forms/uploads/php/files/2ec45c7e0eafeaf23b61cb80ec1e890a/8970454896.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bbe39dd1328---nepadekizuvepivesobarud.pdfIn PDF document text
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c90c3ae5e67---14327218326.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/s9l3vkkgqg2qljmgh0e0jste62/zevamadiku.pdfIn PDF document text
    • https://cmetrix.net/ckfinder/userfiles/files/149685417.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609cb18513f89---tosunozokekukopile.pdfIn PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/788201d898396d0865543ff803656268/nakedibakuj.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/rimuvinune.pdfIn PDF document text
    • http://pro-elec.ru/ckfinder/userfiles/files/xorevavabi.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/kiwulazedapurisivo.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1608104418f1ec---68998089479.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/6f5ff20073647be5fb905dfd9714d779/11781277783.pdfIn PDF document text
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c93ca81a054---jenujidomubadozifogabu.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b84e77050aa---midetukibakekevude.pdfIn PDF document text
    • https://peiitw.com/Upload/ckeditor/files/11337845536.pdfIn PDF document text
    • https://www.caissedesecolesdu5eme.fr/backoffice/ckfinder/userfiles/files/xuber.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/965bbc6b50f31d004c7553ff567f2b1f/metekibuso.pdfIn PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/16089d782be58f---11357579137.pdfIn PDF document text
    • http://saopauloairporttransfers.com/ckfinder/userfiles/files/naboviduvajegipidasowiga.pdfIn PDF document text
    • http://abimobiliare.pl/pliki/File/89401966726.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607ea4d99f898---49759727818.pdfIn PDF document text
    • https://www.syah.org/wp-content/plugins/super-forms/uploads/php/files/401ec3dabb6bf3e4d92267d221ab702a/74408563772.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=how+to+calculate+low+voltage+transformerPDF link annotation
    • 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_off000106e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106E5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011ef7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EF7 17524 bytes
SHA-256: 9efebe2ace709edf99bc5bd1e8af83677ab3c0d1b520f5ebb52acf1fda70e269
font_02_sfnt_off00014d72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14D72 10832 bytes
SHA-256: e3b55ca0baef3f2de76eb53242a7a0b8b3a16dc5bf87bc88df8cbf79ea1843e7

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