Malicious PDF — malware analysis report

Static analysis result for SHA-256 7cef7c01df77fd23…

MALICIOUS

PDF

77.3 KB Created: 2021-09-10 05:48:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a7f38dea976c74fe73cd409be4762cfe SHA-1: 31d44c80d772d08b4461467549d26b91796cfbfb SHA-256: 7cef7c01df77fd234d0ae11d0f8aeafe092c08299ce99053cc689ebd7f854b81
106 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous external links, many pointing to other PDF files hosted on various domains. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates that the PDF functions as a link farm on disposable hosting, suggesting a scheme to distribute or redirect users to malicious content. The ML classifier also strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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=guitar+lessons+pdf PDF link annotation
    • https://kmkmekanik.com/upload/ckfinder/files/womefibosonupotene.pdfIn PDF document text
    • http://vinczeandlaszlo.com/upload/pabupabole.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/cc179304aad9c0bd208546ab6130ea1e/kedosuw.pdfIn PDF document text
    • http://ambulatorioveterinarioilghirlandaio.it/userfiles/files/99694367812.pdfIn PDF document text
    • https://il-gusto.com/images/file/dunapezoxebidaxorax.pdfIn PDF document text
    • https://paperland.bg/uploads/file/27581439798.pdfIn PDF document text
    • http://rdmsrl.it/userfiles/files/rivuxiforuz.pdfIn PDF document text
    • https://tahubunting1.com/contents/files/dobedipodisepazuve.pdfIn PDF document text
    • http://rlangkhan.com/upload/userfiles/files/35954470938.pdfIn PDF document text
    • http://nato-denkmal.de/uploads/file/18810627093.pdfIn PDF document text
    • http://kperrylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/maralagimaxewovulijefi.pdfIn PDF document text
    • http://thewhitmerlawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/peporiwodatabanoda.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a66c20ea54---soremu.pdfIn PDF document text
    • http://satunatc.ac.th/ckfinder/userfiles/files/tilewiki.pdfIn PDF document text
    • https://kasihpaham.com/contents/files/55520288880.pdfIn PDF document text
    • http://dorinhawear.com/admin/fckeditor/editor/filemanager/connectors/php/fckeditor/editor/filemanager/connectors/php/userfiles/file/99203720520.pdfIn PDF document text
    • https://whiteplacard.com/UserFiles/file/39246810006.pdfIn PDF document text
    • http://studiochiodo.eu/userfiles/files/32790174648.pdfIn PDF document text
    • https://rallstarawards.us/nbloom/fckuploads/file/xaradamaxanowanumozinoke.pdfIn PDF document text
    • http://tdsns.ru/userfiles/file/64966049320.pdfIn PDF document text
    • http://specimport.by/files/files/68905320537.pdfIn PDF document text
    • https://85097781.com/upload/files/42419097531.pdfIn PDF document text
    • http://broadviewlibrary.org/uploaded_bvlib/file/fefiraligoz.pdfIn PDF document text
    • http://www.prodomasa.com/ckfinder/userfiles/files/bominaweponufujobigonupu.pdfIn PDF document text
    • http://www.wcd.com.tw/ezadmin/ckfinder/userfiles/files/kedoruxutikapibidaxev.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_off0000cae1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAE1 10632 bytes
SHA-256: 0c62d611553d5e9222427555bebeee5c1af6e8a5aa8fd67fe2148b979556d2d0
font_01_sfnt_off0000e34e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE34E 17100 bytes
SHA-256: 5afbb292186bb528a564b13317af02f4cf15ef55ff698b7c3263775d2b05a509
font_02_sfnt_off00010f67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F67 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1