Malicious PDF — malware analysis report

Static analysis result for SHA-256 81c61f168b4208f1…

MALICIOUS

PDF

79.8 KB Created: 2021-09-09 02:10:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: fb403132e8fb2647ffdc31fc1048dc73 SHA-1: e79dff67ca301106fa750db91ebf50de38342c71 SHA-256: 81c61f168b4208f1afbc450be3ad316c4148e7b9405fd2a7e7b621ea7642b2ec
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to external sites, and heuristics indicate it functions as a link farm, likely for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://mar3ol.com/Files/files/jemuxaraxuwapinubug.pdf In PDF document text
    • http://dietaltop.com/userfiles/files/fapopezudo.pdfIn PDF document text
    • http://wxeina.com/userfiles/files/95296652519.pdfIn PDF document text
    • https://learnrkbin.jugalbandiresearch.com/ckfinder/userfiles/files/salelemubavutamo.pdfIn PDF document text
    • http://prtourusa.com/FileData/ckfinder/files/20210906_FE9CAA6B50128C0C.pdfIn PDF document text
    • http://105chers.netsociality.com/upload/files/34821368359.pdfIn PDF document text
    • https://detectagsafety.com/ckfinder/userfiles/files/23090578665.pdfIn PDF document text
    • http://sunil.kr/uploadfile/fckeditor/file/88082407121.pdfIn PDF document text
    • http://filippodelvita.com/demo/userfiles/file/wenebodogedigije.pdfIn PDF document text
    • https://gagiongvitgiong.com/ckfinder/userfiles/files/mibepixejekutowo.pdfIn PDF document text
    • http://pallenberg-busreisen.de/uploads/files/lapifaxuvubanatupit.pdfIn PDF document text
    • http://star-transform-moscow.ru/uimg/files/27692779159.pdfIn PDF document text
    • http://meyergarden.com/ckfinder/userfiles/files/soxegakineb.pdfIn PDF document text
    • http://preciz.com/uploads/wysiwyg/files/tejedalusaranewevopaxoran.pdfIn PDF document text
    • http://gorod-r.com/userfiles/file/lodivif.pdfIn PDF document text
    • http://babamoleskine.com/files/file/ganusikeru.pdfIn PDF document text
    • http://antoniolescio.net/userfiles/files/30065190332.pdfIn PDF document text
    • http://zkmeiqi.com/admin/ckfinder/upfile/files/nusepinuku.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/161347a33a61af---zosufudam.pdfIn PDF document text
    • http://pomelieagency.com/userfiles/files/52439613646.pdfIn PDF document text
    • https://rusepress.com/uploads/wysiwyg/files/66753126514.pdfIn PDF document text
    • http://gallery4walls.com/upload/editer/file/ledizevekobikevegeraguti.pdfIn PDF document text
    • http://zulassungsservice4you.de/bilder/file/pobasopikuvupununuvedeju.pdfIn PDF document text
    • http://tuyothuyluc.vn/webroot/img/files/67408605544.pdfIn PDF document text
    • http://nwatchonline.com/userfiles/file/wotuvozifav.pdfIn PDF document text
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161348404bef76---77150825248.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=ppsspp+football+games+free+downloadPDF 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://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_off0000d4c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4C9 16928 bytes
SHA-256: d773c58ea0173f1278371c49e492494ac13abbb17b4b30372bfe18e3826106fb
font_01_sfnt_off0001001e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1001E 10976 bytes
SHA-256: 73375c8ee566dc6cda45615c3434f6ee0a5f0d350eab4641f632135535fcdba1
font_02_sfnt_off0001194b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1194B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1