Malicious PDF — malware analysis report

Static analysis result for SHA-256 6d9b5d5e479661c4…

MALICIOUS

PDF

77.4 KB Created: 2021-09-20 08:51:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 479d486a7ff854e7b9734961c653dc85 SHA-1: fa2c4d965f805af660d4bd65c44c235d43248e03 SHA-256: 6d9b5d5e479661c45b3f8a2b38c97c090d210a92975adff67c89e0d2ab89405f
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous external links, with several pointing to PDF files hosted on potentially disposable domains, indicating a link farm or downloader pattern. The PDF_RANDOM_URL_LINK heuristic further supports the malicious intent by identifying an algorithmically-generated URL.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://stagelight.pl/userfiles/files/54603020908.pdf In PDF document text
    • https://foodvellythailand.com/upload/files/ketoverufeder.pdfIn PDF document text
    • http://ambulatorioveterinarioscapindandrea.it/userfiles/files/72134276934.pdfIn PDF document text
    • https://stormester.no/files/file/wuwegubedino.pdfIn PDF document text
    • https://iagclaims.endataclaims.com/ModCoreFilesUploaded/file/jodirezu.pdfIn PDF document text
    • http://mentor-tutor.com/newGroserLikeProject/uploads/files/xewaposugefakuwu.pdfIn PDF document text
    • https://sindicav.com.br/ckeditor/ckfinder/userfiles/files/pemujubaduguwomazorazu.pdfIn PDF document text
    • https://blugarden.eu/file/vuzidoxawav.pdfIn PDF document text
    • https://vatlieutaphu.com/upload/files/37781964474.pdfIn PDF document text
    • http://yokosohk.com/files/fckfiles/file/newumovot.pdfIn PDF document text
    • http://status-go.net/gfx/userfiles/files/xurowuzabakojik.pdfIn PDF document text
    • http://jarosi.hu/files/file/pazagupamukige.pdfIn PDF document text
    • https://mygoaltv.com/ipp/images/uploads/files/47460040070.pdfIn PDF document text
    • http://newo.ru/files/files/64562102701.pdfIn PDF document text
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/81da0a85dd28bae220d64a2cb3ed506f/17936624138.pdfIn PDF document text
    • http://krakow4you.pl/krakow/files/dowodo.pdfIn PDF document text
    • http://tercovci.cz/files/file/zuxikebagagogowiv.pdfIn PDF document text
    • http://hotdeals24x7.com/ci/userfiles/files/74118874525.pdfIn PDF document text
    • http://nc-israel.ru/upload/files/23422576617.pdfIn PDF document text
    • http://xn--2osv9pt2jfpt.com/uploadfiles/files/bisiravebon.pdfIn PDF document text
    • https://motiwalainstitutes.org/userfiles/file/16358175421.pdfIn PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/07f3b82a7cc796ab56dfb3680859f61f/nogiresijelokidiriretadi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=anime+game+download+appPDF 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_off0000cb5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB5B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e372.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE372 10436 bytes
SHA-256: fdd1fa411ad48a856c1418d439bfae9aef48f577e7de22ef7791d0533696bfb7
font_02_sfnt_off0000fadc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFADC 17684 bytes
SHA-256: 50a0e22663305b6b3a93da0dacd89e6e17c6444718e76c3148114eb8b4582a43