Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef966991a9fe480e…

MALICIOUS

PDF

100.4 KB Created: 2021-06-29 06:12:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 3851a490a32bda03dc7c9d9dd56a376e SHA-1: 4a7d3114ab92b5c6afe582dd6f96397f0057f6c0 SHA-256: ef966991a9fe480e9be35c36917e8c2f0b396c1e359c1a7c773be50834509ea1
156 Risk Score

Malware Insights

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

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains a link farm with numerous URLs pointing to compromised WordPress uploads and disposable hosting, suggesting an attempt to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further obscuring its true intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9681

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://baxsporthorses.com/userfiles/file/46494124741.pdf In PDF document text
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/i9ijk9piujt49khobfr9oq6mia/tironotade.pdfIn PDF document text
    • http://hoitruyengiaocodocvietnam.com/uploads/image/files/rawurita.pdfIn PDF document text
    • https://fallsplat.se/file/zulibiganivatidotemejon.pdfIn PDF document text
    • https://next-engineering.com/userfiles/files/7749596950.pdfIn PDF document text
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/16085610ba1ecf---69899447091.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/7lf2jn7hu64v8gotg69lc9hb97/luxawasazijeso.pdfIn PDF document text
    • http://timelessmebel.ru/wp-content/plugins/super-forms/uploads/php/files/5992fe34c3dd5892fea1535bd39ba4db/81430839379.pdfIn PDF document text
    • https://uleshuzataruhaz.hu/files/file/kulagotupos.pdfIn PDF document text
    • http://www.festivalmarrakech.info/wp-content/plugins/formcraft/file-upload/server/content/files/1609ce3aaaf4f9---niwunijupidomolileb.pdfIn PDF document text
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a56566d20ad---lexidowokejogofawi.pdfIn PDF document text
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/9adc3920029eb51d9a7615a02ecf3849/gizigud.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607226cc7efce---kimokibib.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/7topfnq988u2nsvmdusr30ge9f/79220890338.pdfIn PDF document text
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/fd4c5d40deb8181298c741ffa246956e/zidutupajiw.pdfIn PDF document text
    • https://martybermanassociates.com/wp-content/plugins/super-forms/uploads/php/files/dc014356bb39c1b701237be629e4f2d6/xemakosadivujugo.pdfIn PDF document text
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/b76943178b01e0ac5fce9fad2d2c620b/47865145644.pdfIn PDF document text
    • https://www.ltgpartners.com/wp-content/plugins/super-forms/uploads/php/files/d0be68301bbbb2207879e30dbc330354/wilof.pdfIn PDF document text
    • https://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/06a0953ee3b0c6434e2f7f642ede9470/dunelotatibupupuzabisulu.pdfIn PDF document text
    • http://aksaxena.com/bpms/includes/fckeditor_uploads/userfiles/file/43647051992.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098bf032d4b3---11127749853.pdfIn PDF document text
    • https://bbu.vn/Images_upload/files/61126811382.pdfIn PDF document text
    • http://mytmbc.org/fckimage/file/26644261512.pdfIn PDF document text
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607826a94f6c3---referawezowotogegu.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d8f5b5f098c---notanonemadofarugerejaf.pdfIn PDF document text
    • http://thedewakohchang.com/image/upload/File/ipupokodujumozoku.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a71ee5a59c8---89767015780.pdfIn PDF document text
    • http://profisystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16086c55159a0e---zopejosutovuk.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=open+inspect+element+in+chrome+macPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010d0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D0E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012520.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12520 19552 bytes
SHA-256: 93aeee00acb1d1bcb537c66c9fb87649ce2c28be7d5b111e0deb2d35d3fb8bab
font_02_sfnt_off00015602.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15602 16120 bytes
SHA-256: 982e20f1632361179aa692f3b2947f8ed1dc6bd65d5bb5a4735891513c6764b5
font_03_sfnt_off00016b6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16B6B 10664 bytes
SHA-256: 6d28f53099395158b0097e701355657c08e7d6134d83b0c8d3256b8637508d1d