Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef41856282c4e1c2…

MALICIOUS

PDF

75.1 KB Created: 2021-05-06 12:27:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-23
MD5: 865a9214bd5684d2dc211ec675744a94 SHA-1: 431299f03ea447a2fdf9377cd7af4fec68435f46 SHA-256: ef41856282c4e1c28412648c07fabc50de06547c38c054e43f3e188cd5fcf234
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous links to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The document body, though heavily obfuscated, appears to be a lure related to an 'estimation worksheet for kindergarten'. No scripts were extracted, but the presence of numerous external links indicates a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/83d73bd019486526da9be1d9a504bfe8/39007558516.pdf In PDF document text
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/afq8fmbdi2o6mv9ckeqf83qsqn/66146241693.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/16086656a57fe5---91616626008.pdfIn PDF document text
    • https://marbellamohali.com/wp-content/plugins/super-forms/uploads/php/files/97a3da4d927f38273c561f07f6142479/81165957354.pdfIn PDF document text
    • https://charqueadaboavista.com.br/wp-content/plugins/super-forms/uploads/php/files/e0560086ecbfe0dde0d32679109c7622/51147706145.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/aguxebox.pdfIn PDF document text
    • https://monacollection.ua/wp-content/plugins/super-forms/uploads/php/files/e2f5214497718840d2384d1839f8689d/vazilatixepujer.pdfIn PDF document text
    • http://www.morenoroofing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093a05ad798e---zegilejipaful.pdfIn PDF document text
    • https://www.varishastalari.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080bb642713e---73942069413.pdfIn PDF document text
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b9a88a28ac---48072909342.pdfIn PDF document text
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/dd06bfea8a156ac071fceecf68194abe/livegaluzinoxu.pdfIn PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/c93b7b30fabb5488d9a5b3aaa720d9df/nanekutagikopavu.pdfIn PDF document text
    • https://www.helmmsp.ca/wp-content/plugins/super-forms/uploads/php/files/41900707053a69a64ea94f3e31d944d5/basefo.pdfIn PDF document text
    • http://angelojrobles.com/admin_initial_test/userfiles/file/51854839459.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/a116f1beafa8dc70e9f07e9b85aadb29/84199578446.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160815185e1078---talojux.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/3543788fd45535eb24bd699c344aa717/89624616460.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=estimation+worksheet+for+kindergartenPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e882.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE882 5404 bytes
SHA-256: 1757782efcb421f9024ea9eed98ba272d26d083284fa6693793a1c15521ccf1a
font_01_sfnt_off0000facd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFACD 10944 bytes
SHA-256: 9688f104baa1897cc7c007b386afff1815c5d0e12849ed4f4e7bd6747f9af406

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