Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8a169c77a979963…

MALICIOUS

PDF

77.9 KB Created: 2021-09-06 01:04:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 174b0ee5f96341093ff460034ab8dc7f SHA-1: 2f4b2f9ded75713b211d82697f6a45aabba046f3 SHA-256: d8a169c77a979963308f12febe60437518a90392a2c88bc0705e1bcc3d3159cc
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm or redirection scheme. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the structure and URL patterns indicate a malicious intent to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://irlanc.ru/uplcv?utm_term=drishti+ias+history+optional+notes+pdf PDF link annotation
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1607ec71f749ee---8477907108.pdfIn PDF document text
    • https://agrimal.pl/userfiles/file/vemivilexuzinujemaxoju.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b982b005be0---kikakixowonovas.pdfIn PDF document text
    • http://eternoohydro.com/d/files/monodinazazudiginarex.pdfIn PDF document text
    • http://thietkeweblongan.com/upload/files/xijuja.pdfIn PDF document text
    • http://www.gyndoktors.de/ckfinder/userfiles/files/40148217779.pdfIn PDF document text
    • http://thaoduocquyhiem.com/userfiles/image/file/10670463758.pdfIn PDF document text
    • https://tskrea.com/userfiles/file/84868387446.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/1608bf8b24bae8---93394433998.pdfIn PDF document text
    • http://cyc.cz/pictures/clanky/files/8207775501.pdfIn PDF document text
    • https://hsse.cl/files/93011053838.pdfIn PDF document text
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/1611eb43130932---nowepojunuze.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607701484948f---lanubadejunikuzigejej.pdfIn PDF document text
    • http://nitexprofi.cz/userfiles/file/pixikusuk.pdfIn PDF document text
    • http://cephedanismani.com/images/pages/file/dofebetopopiwesaratepoluv.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609609cfcf554---10190724665.pdfIn PDF document text
    • https://heatingboiler.ca/fck_upload/file/mutogesobuge.pdfIn PDF document text
    • https://ivanda-commerce.hr/userfiles/file/13924447070.pdfIn PDF document text
    • https://heykidsletscook.info/wp-content/plugins/super-forms/uploads/php/files/cd31b4885a452947a0435e70d5c70fe0/fokupodugulodojezedi.pdfIn PDF document text
    • https://sckprime.com/wp-content/plugins/super-forms/uploads/php/files/76a791dd4e44f4b723526525a5954558/gexisututoxugeta.pdfIn PDF document text
    • https://www.westcountrystoves.co.uk/wp-content/plugins/super-forms/uploads/php/files/2b68f88c47824669fea84fd64f01eccb/66429203176.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/fa5moh5gmp6f825vvf4mq95a0e/79095776553.pdfIn PDF document text
    • http://accessprecision.com/userfiles/file/11054162141.pdfIn PDF document text
    • http://autoshiftbid.com/fckeditor/userfiles/file/12211348101.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_off0000c6c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6C6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dedd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEDD 10708 bytes
SHA-256: a3416b3fcddfeabf74597d0d9a26be70776e60b5e1d1c1e5df15b04242c37a5e
font_02_sfnt_off0000f766.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF766 19584 bytes
SHA-256: f8a8d121967dcbfa30da1fac66353e59105dfb5544e7f547e44069605945c848