Malicious PDF — malware analysis report

Static analysis result for SHA-256 83be5ed631c12491…

MALICIOUS

PDF

83.6 KB Created: 2021-09-04 08:35:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 0b4780559e075c90bcee2157dbb9ea7c SHA-1: d1e7a360f195a33657c35cf67e551e13838c14f1 SHA-256: 83be5ed631c12491421ed1ce2b61877e0e83067f93b320dd92c5ef562873f70a
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to compromised WordPress sites and other disposable hosting, indicating it functions as a link farm. The ML classifier strongly identified this PDF as malicious, and the heuristics confirm its nature as a link farm designed to redirect users to potentially harmful content. No scripts were extracted, but the primary attack pattern is the distribution of malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 5

  • 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://coretry.ru/uplcv?utm_term=io+link+protocol+pdf PDF link annotation
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/16094df1f4a66c---norodizejiwinowugixad.pdfIn PDF document text
    • http://shipsupply.ru/userfiles/files/jizejufapigafifemijir.pdfIn PDF document text
    • https://www.ideaklinik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16083fd3d56125---rafunetuwus.pdfIn PDF document text
    • http://www.lauricedale.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160ae412c74a5c---65482290435.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1611d30441de73---dazosezexokedub.pdfIn PDF document text
    • https://anmoul.com/userfiles/file/74975841456.pdfIn PDF document text
    • http://avtoarka.ru/wp-content/plugins/super-forms/uploads/php/files/c06f2a0655577af68b29de850b09c3e5/pezilipuxob.pdfIn PDF document text
    • http://tunglamgarden.com/images/fck/file/zomimisal.pdfIn PDF document text
    • http://szakkepzosiklos.hu/upload/file/wanasopesozuvubapip.pdfIn PDF document text
    • https://www.mysmilestudios.com/wp-content/plugins/super-forms/uploads/php/files/094c33f2a0eac7a1899a088defd90a86/5334629639.pdfIn PDF document text
    • http://wcsps.com.tw/ckfinder/userfiles/files/vivajixa.pdfIn PDF document text
    • http://fsgpj.com/upfolder/e/files/20210629030903.pdfIn PDF document text
    • http://www.lavalledesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612e8c28b5b05---mojogafuz.pdfIn PDF document text
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/b2c028f84766e39a615e1729f2070793/92656992709.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160f301bcf2001---11710686816.pdfIn PDF document text
    • http://alfonsoguiggiarchitetto.it/userfiles/files/56989826583.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/78624240939.pdfIn PDF document text
    • http://xn--80aesyq.xn--p1acf/files/file/netagixipefipov.pdfIn PDF document text
    • http://elite-nails.pl/Upload/file/jorizejofafugupagi.pdfIn PDF document text
    • http://donghozibistore.com/luutru/files/biwubegafudagupuxudal.pdfIn PDF document text
    • http://hong-tour.com/FileData/ckfinder/files/20210730_D6FCD1FB3C2F1A43.pdfIn PDF document text
    • http://garderoba.sk/images/_file/lamifefivikukafeta.pdfIn PDF document text
    • http://hometextiles-consultant.com/ckfinder/userfiles/files/mupupedene.pdfIn PDF document text
    • http://coalcreekcentenary.com/clients/5/52/52f735e63eff8706e1a2a73a20aef632/File/wujididobobisebali.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_off0000e2dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2DC 10196 bytes
SHA-256: 45f11b73467ba32f4d9912465b4c4b85913359ecfb6b0322e1ff0c05aea61f6b
font_01_sfnt_off0000f9b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9B5 18868 bytes
SHA-256: b1e3180ffffbfdbbe2f4bd28b5531dabd059239f7fd738f38a650aa3e95180eb
font_02_sfnt_off00012905.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12905 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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