Malicious PDF — malware analysis report

Static analysis result for SHA-256 551f6a3fab5329e6…

MALICIOUS

PDF

82.9 KB Created: 2021-09-19 05:37:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 844609d3629b058818938677783f5ed4 SHA-1: 28571cf1db66ac197468010d78e3eeb6314133ae SHA-256: 551f6a3fab5329e6101a92fbde97da9f7b7d6c3de511bbe46284bbdc98bc0edc
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be compromised or disposable hosting. Heuristics indicate this is a link farm designed to direct users to external content. The ML classifier strongly flagged this PDF as malicious, suggesting it's part of a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://wastran.ru/uplcv?utm_term=australian+wicket+keeper+list PDF link annotation
    • http://privateeducation.sg/verzsape/demo/upload/admin/files/nosojevixowisasog.pdfIn PDF document text
    • http://ballmillfactory.com/d/files/rezibagidobemexidaneriwa.pdfIn PDF document text
    • http://ijfbn.com/editor_up/6759733369.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/161357536b63c7---59061919038.pdfIn PDF document text
    • https://aadhaarretail.com/administrator/imagetemp/file/sojudewaxu.pdfIn PDF document text
    • https://groupunsur1.com/contents/files/luxegiloximonufa.pdfIn PDF document text
    • http://celyroknaterase.sk/editor_uploads/system/files/90166578825.pdfIn PDF document text
    • https://norservis.cz/files/files/20750909320.pdfIn PDF document text
    • http://thietbiytedaibao.com/media/files/29982050663.pdfIn PDF document text
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/924c9a473960f44377a35cc1699b7ef9/kavekutupebos.pdfIn PDF document text
    • https://absoluteanytime.com/media_file/files/files/627075996.pdfIn PDF document text
    • http://transcash.com/ci/userfiles/files/79038073585.pdfIn PDF document text
    • https://euronuts2009.ge/files/files/3765932546.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613b2cbb3c05b---puvitudigavaz.pdfIn PDF document text
    • https://www.studiorosaliabusco.it/ckfinder/userfiles/files/liwitoromupit.pdfIn PDF document text
    • http://www.siscbolivia.com/admin/uploaded/fck/file/4065972049.pdfIn PDF document text
    • http://clubselectionvoyages.com/images/file/japux.pdfIn PDF document text
    • https://postelezmasivu-liberec.cz/ckfinder/userfiles/files/30432803489.pdfIn PDF document text
    • http://mqskin.com/luutru/files/44900035603.pdfIn PDF document text
    • http://www.ez4parcel.net/upfile/files/2021/09/18/37412934398.pdfIn PDF document text
    • http://studiorapizza.it/userfiles/files/lokiviwubewupoguwenejibiv.pdfIn PDF document text
    • http://ufcnagykanizsa.hu/userfiles/file/pebasizisurovalugitor.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/k3kofu5slish8sjok48ja8rp8o/tewamiletesatejologoku.pdfIn PDF document text
    • http://tlznailspa.com/media/files/92562228045.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_off0000dc64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC64 18652 bytes
SHA-256: 2a9762cdb781e42586e74c391220a5d824336d5b6b24c633d0913ec860cb01d0
font_01_sfnt_off00010d76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D76 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001258d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1258D 10508 bytes
SHA-256: 9c09db600fed5a9f9c863f733867135c55e01fb4648bb444d7bbf1b9b4b223f6