Malicious PDF — malware analysis report

Static analysis result for SHA-256 d941d1c8b8ae962d…

MALICIOUS

PDF

80.2 KB Created: 2021-09-10 20:28:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: cc8d5e572a8c8118a4e395290faf1f2c SHA-1: 63dbae065cefd355edc13e8065a8ef8f0fa62ab6 SHA-256: d941d1c8b8ae962db17b8a7bf7a3519043a500a6dfaf20474f367e1ef0360b23
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by an ML classifier. It contains numerous embedded URLs, many of which point to disposable hosting and appear to be part of a link farm, a common tactic for SEO manipulation or distributing malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this malicious intent. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the heuristics indicate a pattern of directing users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 4

  • 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://crewmak.ru/uplcv?utm_term=no+deposit+bonus+codes+2020+aus PDF link annotation
    • https://daulte.com/ckfinder/userfiles/files/8068178557.pdfIn PDF document text
    • http://rideco.hu/upload/file/59298590338.pdfIn PDF document text
    • http://radiosalsa.fr/php/rs/filesupload/file/wifizaxesuxatudevegir.pdfIn PDF document text
    • http://ikra-ekb.ru/files/fckeditor/file/kasuzinunidip.pdfIn PDF document text
    • https://brigitte-farner.ch/userfiles/files/kozokozebavizu.pdfIn PDF document text
    • http://gat-asset.com/CKEdit/upload/files/sezatatunajuv.pdfIn PDF document text
    • https://negaratoto.com/contents/files/begipab.pdfIn PDF document text
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/e1234f64744dcf34498c7635f4688c82/zexuvazuxagenematatalini.pdfIn PDF document text
    • http://rudolphi.nu/userfiles/file/6724720110.pdfIn PDF document text
    • https://coevent.ru/upload/files/fagopunixofaduwufo.pdfIn PDF document text
    • https://fotobolfestmeny.hu/mvc/userfiles/file/raxatalupilaluwirenenatu.pdfIn PDF document text
    • https://unitytradefze.com/ckfinder/userfiles/files/39566525421.pdfIn PDF document text
    • https://ceccarbotosani.ro/userfiles/file/22729326797.pdfIn PDF document text
    • http://sieuthimaynhapkhau.com/upload/files/zagafipokaliwowojapego.pdfIn PDF document text
    • http://studiodrago.eu/userfiles/files/dogezujodugadoluvakirezeb.pdfIn PDF document text
    • http://iswii.net/ckfinder/userfiles/files/50398187800.pdfIn PDF document text
    • http://evrofurnitura.by/elax-furnitura.ru/uploads/files/felezezuzenajov.pdfIn PDF document text
    • http://leton.pl/userfiles/file/65777345321.pdfIn PDF document text
    • http://goldenpeak.it/userfiles/files/bidipubosibufunez.pdfIn PDF document text
    • http://studiocommercialedelpiano.it/userfiles/files/90348140248.pdfIn PDF document text
    • http://bannhuaduong.net/upload/files/zulesiwitekemulenorup.pdfIn PDF document text
    • http://juditphotography.com/picture/userfiles/file/makuxawag.pdfIn PDF document text
    • http://jungam21.com/upfiles/file/1630469689.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/1612ea41601cf3---vadigopilavupagedupavip.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_off0000d142.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD142 18712 bytes
SHA-256: 245f8f2029d608951a3e36d512ce002f1bf2f9a42e906927ad2eb1f9cf14e90e
font_01_sfnt_off00010221.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10221 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011a38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A38 10820 bytes
SHA-256: adfd2b032972f618cfbd917c6333c02d06b50b40a058f289e9446266ea8d1461