Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8b3e10342d732bd…

MALICIOUS

PDF

80.7 KB Created: 2021-10-05 09:30:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 9a5826b1a01b002ab5659af48332df09 SHA-1: 8b7011a0e04167dff4a450d428ddc931f58c0e84 SHA-256: d8b3e10342d732bdebcfe77b1823925164f08a909aeff57d959a01a3e9552ccc
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs that function as a link farm, with many pointing to compromised WordPress sites. The ML classifier strongly indicated maliciousness, and the structure suggests an attempt to manipulate search engine results or redirect users to potentially harmful content. No scripts were extracted, but the extensive use of external links points to a phishing or SEO poisoning attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://inwebjor.ru/uplcv?utm_term=pdf+of+beehive+class+9 PDF link annotation
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615b77dd9971a---gibubigemosunivojolidoju.pdfIn PDF document text
    • http://kipia-nn.ru/userfiles/file/majofidijijogekexuxal.pdfIn PDF document text
    • https://atlanticcompact.org/userfiles/files/99098139702.pdfIn PDF document text
    • https://weilaimachinery.com/userfiles/files/mesodilosefutetome.pdfIn PDF document text
    • http://cobmedia.hu/include/42517161743.pdfIn PDF document text
    • https://oz.korytnica.eu/data/files/79668939487.pdfIn PDF document text
    • http://stroyindustry.com/userfiles/file/dipejujusopubajepamo.pdfIn PDF document text
    • https://interior-mark.com/ckfinder/userfiles/files/99565587185.pdfIn PDF document text
    • https://rubfila.in/files/file/27135421911.pdfIn PDF document text
    • http://kperrylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/19311569759.pdfIn PDF document text
    • http://aaas.handyfriendship.com/upload/files/lapeso.pdfIn PDF document text
    • http://www.hzkontejnery.cz/ckfinder/userfiles/files/8039078951.pdfIn PDF document text
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/a67da9a0bf84e0663ba85a5a4cacdff5/wovonijisudesuju.pdfIn PDF document text
    • http://hoadon-dientu.net/images/files/puzaxiwi.pdfIn PDF document text
    • http://quiltingacademy.net/fckeditor/userfiles/file/3885930118.pdfIn PDF document text
    • http://architettogherardi.eu/userfiles/files/wamujarilifusupupezavoma.pdfIn PDF document text
    • http://quangphong.vn/uploads/image/files/63634922582.pdfIn PDF document text
    • http://vertex-decor.com/userfiles/file/76764164793.pdfIn PDF document text
    • http://restravel.ru/ckfinder/userfiles/files/93225462906.pdfIn PDF document text
    • http://onlinetradeshow.ir/uploads/files/tugeridudido.pdfIn PDF document text
    • http://mdbim.pl/ubezpiecz/obrazy/file/wonubigatizesag.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/16150631e19ffc---25086881815.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1612e9eef7f245---71937333217.pdfIn PDF document text
    • http://hyundai-baoloc.com/luutru/files/suseb.pdfIn PDF document text
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16142dfd7120d8---jobakaxawumup.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_off0000d5ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5AD 18188 bytes
SHA-256: b57199a8dc1460b6c03bca7d48de87ffccdbf781e3ac920b020e6753ce5149b6
font_01_sfnt_off000104b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104B6 10648 bytes
SHA-256: 004949f577028de75349fdde420aa2bf7fb17b4c84a9882d8f8030ec0c34a0dc
font_02_sfnt_off00011d40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D40 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1