Malicious PDF — malware analysis report

Static analysis result for SHA-256 b33b1b906da7a097…

MALICIOUS

PDF

84.5 KB Created: 2021-09-16 20:58:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 9c2122da9b31dc3b78e28b38f9a599c7 SHA-1: 2ada33df24204aba81b8a2a981a0a53039f93643 SHA-256: b33b1b906da7a09744d9ba1dcfe1048b6cb2c51ceb64b25c8ccf3ddd5023fc50
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to suspicious PDF files hosted on various domains, suggesting a link farm or redirection mechanism. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for these links, further supporting a malicious intent to distribute harmful content or phish users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://wotfiles.com/ckfinder/userfiles/files/vubuvidogufap.pdf In PDF document text
    • http://dakdekkersindex.nl/images/uploads/35472399368.pdfIn PDF document text
    • http://kiuruvedenlukio.fi/tiedostot/file/muwotepi.pdfIn PDF document text
    • http://star-transform-moscow.ru/uimg/files/sidatulujixi.pdfIn PDF document text
    • http://www.koeru.eu/failid/file/roxepejinifolovoba.pdfIn PDF document text
    • https://ardiinerkh.mn/uploads/userfiles/files/96682593970.pdfIn PDF document text
    • http://keralatravelpath.com/uploads/file/jeragumenukirazazi.pdfIn PDF document text
    • http://nhahanghienminh68.com/upload/files/50069619957.pdfIn PDF document text
    • https://herfection.herfection.tw/upload/ckfinder_temp/files/20210914180027.pdfIn PDF document text
    • http://www.deopendeur.org/imgUser/file/bajivotapu.pdfIn PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/f494e5db5b250921c38172c892ea6305/gubufakinifidirixa.pdfIn PDF document text
    • https://thic.muki001.com/plugin/ce1/ckfinder/userfiles/files/81356265182.pdfIn PDF document text
    • http://jsdarvin.com/files/15210019888.pdfIn PDF document text
    • http://primeasset.hu/fileok/file/13274142409.pdfIn PDF document text
    • https://cooperadora.grupocreartel.com/documentos/archivos/tabepofupodutubi.pdfIn PDF document text
    • https://seedcambodia.org/htdocs/cljr/data/files/69494808421.pdfIn PDF document text
    • https://infoenergie-loire.org/userfiles/file/wemoguwewupudasetobe.pdfIn PDF document text
    • http://e68momo.com/shopadmin/upload/files/giwotagezokifunugisebome.pdfIn PDF document text
    • https://china-glass-mosaic.com/userfiles/files/20210906_160343.pdfIn PDF document text
    • http://ahdjcm.com/upload/files/11030132432.pdfIn PDF document text
    • http://solarexperte.ch/fckeditor/editor/images/file/36478995251.pdfIn PDF document text
    • http://www.zywawiara.pl/pliki/91369264542.pdfIn PDF document text
    • http://mn-print.ru/ckfinder/userfiles/files/48310307397.pdfIn PDF document text
    • http://creativetechno.in/userfiles/file/18297130679.pdfIn PDF document text
    • http://starwindows.ie/ckfinder/userfiles/files/negose.pdfIn PDF document text
    • https://artofsurfing.com/preview/ckfinder/userfiles/files/xuxenonijatinoxavisimut.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=mclean+borderline+personality+disorder+pdfPDF 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_off0000e19d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE19D 18848 bytes
SHA-256: f57ed6b26b0e63946e6fb6f24665da2864d7fe13f21c2d857908c9c7f584caad
font_01_sfnt_off0001130e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1130E 10860 bytes
SHA-256: 17aa1316edd901e2cc2130dc68bb6f461c3f54a7c39206acea542c098b940a8b
font_02_sfnt_off00012c17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C17 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1