Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c879ea7f4019354…

MALICIOUS

PDF

87.0 KB Created: 2021-09-03 08:53:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 6b17b934e2353d5e7cfbc82b6f3893de SHA-1: a0850b8c00f942574a55d86b02d9bb0fa34ca3cd SHA-256: 7c879ea7f401935414dfc20197f4411bf334f73881e5dfbb22ba8350bfd3ffa6
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags this behavior. No scripts were extracted, and the document body is unreadable binary data, suggesting the malicious functionality is embedded within the PDF structure itself.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://myconnect-thailand.com/image/upload/File/72168950341.pdf In PDF document text
    • http://usmleworkout.com/files/file/lunutu.pdfIn PDF document text
    • http://xn--80aatg4aaaddkhfhbf3evf.xn--p1ai/ckfinder/userfiles/files/42612504574.pdfIn PDF document text
    • http://www.studiolegalefusimorelli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b1f9e840a2---66784113988.pdfIn PDF document text
    • https://123natura.com/stockages/files/zojaxotibalib.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c4fc006fbb2---lifanabewapekidatimil.pdfIn PDF document text
    • http://lookkorea.net/userfiles/file/21157372621.pdfIn PDF document text
    • http://xn--h1acbpobggs.xn--p1ai/data/files/47700876357.pdfIn PDF document text
    • http://1careglobal.com/upload/files/99039523131.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/hhqu1en5glpbrtvqukr3ptg546/talurojagejuterabulixava.pdfIn PDF document text
    • http://ambulatorioveterinariocamali.com/userfiles/files/tajotowonebuji.pdfIn PDF document text
    • http://jinanxintiandi.com/userfiles/files/64582758736.pdfIn PDF document text
    • http://harringtonassociateslaw.com/Test/JabzMedicalBillingService/userfiles/file/zuxotizexaxavokiromon.pdfIn PDF document text
    • http://cuakeobinhduong.com/upload/files/31107423703.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/usowipijavug.pdfIn PDF document text
    • http://setadijital.com/img/userfiles/files/33402544445.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160bd332cdcb1e---sefagimulor.pdfIn PDF document text
    • http://emke.hu/uploads/ckfinder/userfiles/files/takevudaxofa.pdfIn PDF document text
    • https://sitebyside.ru/wp-content/plugins/super-forms/uploads/php/files/97d0602340c3454c09933ce593224bd1/powapu.pdfIn PDF document text
    • http://sevimticaret.net/userfiles/file/99704495620.pdfIn PDF document text
    • http://shinyoungvalve.com/userData/board/file/maleleg.pdfIn PDF document text
    • https://godahoian.com/app/webroot/upload/files/92905067682.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/16113762fa84c2---40544219034.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=descargar+lista+de+verbos+regulares+e+irregulares+en+ingles+pdfPDF link annotation
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072ba85eefc1---67637368732.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_off0000e7b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7B6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ffcd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFCD 11104 bytes
SHA-256: 7f042e0f0967ec1b93c38189f6984d6f93a0513621c55dca8ae4ded99b8dc5eb
font_02_sfnt_off00011969.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11969 20352 bytes
SHA-256: ba3ea39dc77750c3e1a39464a7ef81165e0421e91c8f45de8c5802be4402e12b