Malicious PDF — malware analysis report

Static analysis result for SHA-256 a025454d0a4294f9…

MALICIOUS

PDF

82.4 KB Created: 2021-08-19 17:24:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 3ed3aa554f5a4115422310994c65ae91 SHA-1: c37d79b987e004fcf9261b66f114c849a10a521a SHA-256: a025454d0a4294f9f0ef43092593bfd70a11ee72585e8f97c4cfeddeb91406d5
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites utilizing the Formcraft plugin for file uploads. These links appear to be part of a link farm designed to manipulate search engine rankings or redirect users to malicious content. The ML classifier strongly indicated maliciousness, supporting the assessment of a link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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=introduction+to+topology+pure+and+applied+by+colin+adams PDF link annotation
    • http://www.peopleoftheheath.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072735d1d964---65937901896.pdfIn PDF document text
    • http://www.naturhalles.fr/fckeditor/userfiles/file/5358635684.pdfIn PDF document text
    • http://bm-shower.com/userfiles/files/vogodawesafubuzek.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606fb4d37ee06---tiwozaxitojegubazeze.pdfIn PDF document text
    • http://xn--2-140-swe8h.xn--p1ai/files/59192174619.pdfIn PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16089d568e0763---51624337470.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/160bb6124e29e4---mubimitanekagem.pdfIn PDF document text
    • http://zkmeiqi.com/admin/ckfinder/upfile/files/19403072292.pdfIn PDF document text
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/91078a51b46eb06d9f19f1b4c59d2546/podenonipomexogoxudarisip.pdfIn PDF document text
    • http://sys-svinding.dk/userfiles/file/junemomevuvozanubum.pdfIn PDF document text
    • http://extrastyle.ee/ckfinder/userfiles/files/85346616021.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b977149b612---viwejivokiraxagewasuz.pdfIn PDF document text
    • https://alirezamirmohammadi.com/images/upload/files/14944241209.pdfIn PDF document text
    • http://fusheng-vietnam.vn/admin/webroot/upload/image/files/xopetag.pdfIn PDF document text
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/7738806db6e19f6076bf3d0ed7f38e66/dupetu.pdfIn PDF document text
    • http://duszek-lasu.pl/userfiles/file/kexal.pdfIn PDF document text
    • http://camel-republic.com/media/userfiles/files/jununosisuzipog.pdfIn PDF document text
    • http://carrollcountylawyers.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/72590424328.pdfIn PDF document text
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/52b21bac68b55e5c175d0c242fb7294b/42403871110.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160880060cb902---93986132320.pdfIn PDF document text
    • https://www.hotelamoha.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608e782de19ff---36099590915.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160983d482d9a8---kazukurovipukeb.pdfIn PDF document text
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/160929dc960352---wojibudidivibakojo.pdfIn PDF document text
    • http://villaturri.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609f3828b09e0---jajusowiko.pdfIn PDF document text
    • https://tims.ro/ckfinder/userfiles/files/joravubipopajejabovola.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_off0000dc56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC56 17220 bytes
SHA-256: 1a6b40923b1798188842a2fc8baeea9b98791530c33c69253b7059b5dd7a7081
font_01_sfnt_off0001096e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1096E 11164 bytes
SHA-256: e83bc20109e5c169c110d2228c2b2eb098f28224cba3bf60cddb105c3b5e3ce7
font_02_sfnt_off0001231e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1231E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1