Malicious PDF — malware analysis report

Static analysis result for SHA-256 221fa5f61c0f884d…

MALICIOUS

PDF

80.3 KB Created: 2021-09-02 16:10:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: af291076c73e5feabaaa3d57136122a9 SHA-1: 74814a1b1109bed7519a016f0b8a879e32bf282e SHA-256: 221fa5f61c0f884d08bbf61a174947cb038be15604182a9b6186eeccf9a2cdf6
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file exhibits characteristics of a link farm, with numerous embedded URLs pointing to various domains, many of which appear to be compromised WordPress sites. The ML classifier strongly indicates maliciousness, and the heuristic firings suggest a deliberate attempt to create a link farm for SEO manipulation or to host further malicious content. No scripts were extracted, but the overall structure and URL distribution point to a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://laborke.ru/uplcv?utm_term=chemistry+of+coumarins+pdf PDF link annotation
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/iu93pru91f9nrcrt4p24o7fon0/ludalativ.pdfIn PDF document text
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/dkev2b9fpm187oevptqlj34kj1/4656583094.pdfIn PDF document text
    • https://beautydiction.com/ckfinder/userfiles/files/872189375.pdfIn PDF document text
    • https://urbanplace.me/wp-content/plugins/super-forms/uploads/php/files/dc976f452dfd9134f7a674df819c3293/xuxuwa.pdfIn PDF document text
    • http://5m-tti.com/uploads/image/files/65960352880.pdfIn PDF document text
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/16d688f147b1c5f6c9a32de784c03394/megog.pdfIn PDF document text
    • http://betheaskssd.com/flash/betheaskssd.com/file/ruseloxokugabarusapo.pdfIn PDF document text
    • https://seeandhearbetter.ie/img/shop//contents/99723105680.pdfIn PDF document text
    • http://fairview58.org/clients/b/b5/b5cf5456a34e3fefef15e35162a7177a/File/45485965303.pdfIn PDF document text
    • https://propertiproperty.com/Uploads/userfiles/files/80479520487.pdfIn PDF document text
    • http://cancunday.com/travela/img/files/42862886676.pdfIn PDF document text
    • http://isvpro.com/custom/files/32135043646.pdfIn PDF document text
    • http://bscsaoner.in/ckfinder/userfiles/files/43400572195.pdfIn PDF document text
    • http://mstreatmentadvances.com/userfiles/files/167738668.pdfIn PDF document text
    • https://roadtoring.com/wp-content/plugins/super-forms/uploads/php/files/b8627680bd1142b73c269d1e9b5d842b/36263297498.pdfIn PDF document text
    • http://peaceinsrilanka.lk/userfiles/file/veguvepetomunok.pdfIn PDF document text
    • http://bouncebodysupplements.com/newerac2c/userfiles/file/16469383704.pdfIn PDF document text
    • http://serdceprirody.ru/userfiles/file/99543359300.pdfIn PDF document text
    • http://qbcar.ru/ckfinder/userfiles/files/nujojub.pdfIn PDF document text
    • http://regimhotelierbucuresti.com/images/userfiles/89657619317.pdfIn PDF document text
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e1ba204e89---dikiluputaralujasak.pdfIn PDF document text
    • http://dgkno.cn/upload/xenojopuzazirexuwurofijoj.pdfIn PDF document text
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/37d0900e2c2cb1c17455dda3450a61a5/83715911228.pdfIn PDF document text
    • http://daindnc.com/fckeditor/userfiles/file/jabitokabutawujitumarir.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_off0000cfb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFB9 19244 bytes
SHA-256: 3d5b3e63904473fcaf60deb0e3720c83c9fc064f966dbf7c30e547f704339b8e
font_01_sfnt_off000101eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101EB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011a02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A02 11084 bytes
SHA-256: 00bfb257482d235a8d6bd91740e6793533270e51ebcfb877b159aa7930506b5f