Malicious PDF — malware analysis report

Static analysis result for SHA-256 87fce2558a15d06c…

MALICIOUS

PDF

73.9 KB Created: 2021-09-30 11:55:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 0a00950ecca6ebfe263ed8d1611f2d35 SHA-1: cddb1ca159e17999349d1f69242315483846b956 SHA-256: 87fce2558a15d06cbda2f5ab911dc16b9489e4933fe0f23bd5a9d1667aec89b2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate it functions as a link farm, directing users to compromised WordPress uploads and disposable hosting sites, likely for phishing or malware distribution. The presence of embedded URLs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggest an attempt to obscure the final malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9939

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://nomylo.ru/uplcv?utm_term=android+processor+names PDF link annotation
    • https://pass-eco-energies.com/ckfinder/userfiles/files/rufafubowa.pdfIn PDF document text
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615222bb9d634---80653064931.pdfIn PDF document text
    • http://fogathajtohirek.hu/fckfiles/file/95868283215.pdfIn PDF document text
    • http://www.portaldasfreguesias.com/portugal/vianadocastelo/vianadocastelo/geraz_do_lima_sta_maria/ckeditor/ckfinder/file/19793732867.pdfIn PDF document text
    • http://naturalwonders.com/uploads/files/mevonafuki.pdfIn PDF document text
    • http://mictrogiang.com/userfiles/files/juzabofaloje.pdfIn PDF document text
    • https://mihalex.by/files/files/74867490682.pdfIn PDF document text
    • http://altiro.nl/home/tjerk/file/wadusaxufijasizovuwasirop.pdfIn PDF document text
    • http://webinaris.org/ckfinder/userfiles/publics/files/vulosilopekabenumakired.pdfIn PDF document text
    • http://limeitec.com/upfiles/editor/files/pubebatapib.pdfIn PDF document text
    • http://eyela.kr/uploadfile/fckeditor/file/42010828571.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/16143668be177d---xugupowa.pdfIn PDF document text
    • http://tt-ural.su/admin/ckfinder/userfiles/files/fikojul.pdfIn PDF document text
    • http://lobi.md/userfiles/file/nuvopinineluxalekivob.pdfIn PDF document text
    • http://baschin-heizung.com/meineBilderAlbertGrundschule/file/fevidejewowevivomewimavif.pdfIn PDF document text
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16137db076249a---podaparalipezodatiluzera.pdfIn PDF document text
    • http://tiszaladany.hu/upload/file/pegipiwadisuv.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/161303319e5518---83774822367.pdfIn PDF document text
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/be6jfeba57lgmvpdeme2ppk9vv/61526199182.pdfIn PDF document text
    • http://gesht.ru/admin/ckfinder/userfiles/files/pevapajijiwagufajazabu.pdfIn PDF document text
    • https://mangallagn.com/images/file/pijurutotef.pdfIn PDF document text
    • https://mamadona.ru/ckfinder/userfiles/files/rujixebimageroloj.pdfIn PDF document text
    • https://nguyenthelong.net/userfiles/files/59830983290.pdfIn PDF document text
    • http://polymer-optix.de/userfiles/file/bumuwo.pdfIn PDF document text
    • https://laps.pl/userfiles/file/jalafaxesexutegiriwimera.pdfIn PDF document text
    • http://hyundainhapkhau.net/upload/files/xifofakafebi.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_off0000bbdb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBBDB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d3f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3F2 10512 bytes
SHA-256: 80ffecc7b131c840cf3e2eee5d17e97e2461808d55b8135178bc689271bfea4a
font_02_sfnt_off0000ebcd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBCD 17780 bytes
SHA-256: 9538f575ad06fb7c43d2a9fb1b4ca87a77d63cf69c24eba94129d38853399065