Malicious PDF — malware analysis report

Static analysis result for SHA-256 677957fc6a42158f…

MALICIOUS

PDF

77.5 KB Created: 2021-06-19 23:34:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: 940b8ba0474ebc4a169f84c73cd51559 SHA-1: 39ad6618aa98ea923c29970a26fb0603218d204a SHA-256: 677957fc6a42158fddb7fd287ee6a635e85c5e5506812b5779e25737e9576dfb
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of embedded URIs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users. The ML classifier strongly indicates malicious intent, likely to facilitate further compromise or phishing. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://grandp.ru/userfiles/file/32794963202.pdf In PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/16072bc88a34ac---pijipulinuwa.pdfIn PDF document text
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/160a6db0a2f2c5---38199009555.pdfIn PDF document text
    • https://stallion-international.com/userfiles/file/38714627282.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cad5a0a92c---remuvogafu.pdfIn PDF document text
    • http://www.xpresswedding.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097286178cdd---20302859423.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160b99741a4e99---wifevifenoxunilo.pdfIn PDF document text
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16098cba94cd19---doniluxejuzidugemurigidux.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/20a0c4f4b93cd4e2e3242444f9395ca2/73840506358.pdfIn PDF document text
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160b863034c310---pinetarekifakefadavel.pdfIn PDF document text
    • http://nexxosrealty.com/userfiles/files/bamivowutaxaxofo.pdfIn PDF document text
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/35e8853a11b33066e1fa39a004b8561d/23172269990.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160ac0267349b3---99774410572.pdfIn PDF document text
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/bfc4b8aa133f3c638407f8fe0ffba086/64087968069.pdfIn PDF document text
    • https://baodinhsolar.com/wp-content/plugins/super-forms/uploads/php/files/3od5a2vdu0uoo0r8qvd90vqcaf/88579771721.pdfIn PDF document text
    • https://premiumvipbusiness.com/wp-content/plugins/super-forms/uploads/php/files/f2e1cb82ec894266fa4068bedaf6d4b8/toluwetila.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=dm+ukulele+chord+chartPDF link annotation
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f4b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4B4 5064 bytes
SHA-256: ccbfe4f6991f94e1042c8f6fdec0ced3cf1bb82ce01e7eb9332be752c1413deb
font_01_sfnt_off000105c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105C4 10636 bytes
SHA-256: 278bc101c04b2989da901ccd60a56829e3e8cb547ddc5866b68b78693f2ac30e