Malicious PDF — malware analysis report

Static analysis result for SHA-256 217641e5cc420b92…

MALICIOUS

PDF

68.3 KB Created: 2021-09-26 17:58:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 0098f625573609fac09da842cbaaa4cb SHA-1: 88bcb01706ae93d4ba48c5f9ff0d5e6250fd501b SHA-256: 217641e5cc420b92f2d1b6e52d2cb90829bedd4a543910865ae7bb064d1a33e1
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, with a high heuristic firing indicating it's a link farm on disposable hosting. The ML classifier also flagged this PDF as malicious. While no scripts were explicitly extracted, the PDF structure and embedded links suggest an attempt to redirect users to potentially malicious sites, aligning with spearphishing attachment tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

Heuristics 4

  • 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://xn--o39a91gvwm83kbsn.com/FileData/ckfinder/files/20210911_7DADF4EF6683E6C8.pdf In PDF document text
    • http://startent.ru/SITE/files/editor/file/zidaxebet.pdfIn PDF document text
    • https://alternatifhirdavat.com/upload/ckfinder/files/lepivuv.pdfIn PDF document text
    • http://pogologistics.com/ckfinder/userfiles/files/xuvupivotipaki.pdfIn PDF document text
    • http://ternovykh.ru/content/file/70103357807.pdfIn PDF document text
    • https://kinizsibank.inweb.hu/_user/file/bakuzo.pdfIn PDF document text
    • http://olympiad-bigben.ru/ckfinder/userfiles/files/kenosomexovusawetusokon.pdfIn PDF document text
    • https://hondaotohaiphong.vn/upload/files/85018360160.pdfIn PDF document text
    • http://quangcaosms.org/media/ftp/file/88408051867.pdfIn PDF document text
    • http://miyagi.chi-kara.net/Upload/files/14551114825.pdfIn PDF document text
    • https://semsaesp.com/ckfinder/userfiles/files/pilusetuwajabepag.pdfIn PDF document text
    • http://www.aunay-sous-auneau.fr/ckfinder/userfiles/files/48792734468.pdfIn PDF document text
    • https://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/4d1422af0f8c86e1a14b51a7f588c7ff/81358209251.pdfIn PDF document text
    • http://fra2ange.it/userfiles/files/tomegob.pdfIn PDF document text
    • http://klusjesindex.nl/images/uploads/zovakipar.pdfIn PDF document text
    • http://hrudolf.com/userfiles/gokilevilurekefuwigu.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/6c2467f0cd0268fbe2d585fc2eb01805/lisidoja.pdfIn PDF document text
    • https://dampinggame.com/calisma2/files/uploads/fikabitonunetasef.pdfIn PDF document text
    • http://thermogroup.ru/uploads/files/meragudanofenuginejad.pdfIn PDF document text
    • https://cursosadistanciayonline.com/medios/files/7451030866.pdfIn PDF document text
    • http://nawoo.net/userData/board/file/rorejago.pdfIn PDF document text
    • http://tianfonmm.com/d/files/zonulonog.pdfIn PDF document text
    • https://arabadvertise.com/userfiles/files/faged.pdfIn PDF document text
    • http://duhochoangthanh.com/upload/files/suritejijasudofowalane.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=android+studio+cloud+databasePDF 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_off0000ae63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE63 10584 bytes
SHA-256: 03cc85e9e8836910cd065cf81887ed9c3ab324e81fd2a8ef0be3e891aab07f77
font_01_sfnt_off0000c6b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6B9 14892 bytes
SHA-256: aaaa7f6321cb86dbc7694e24f92052d8ec04bac5dd6cef9c6db039bdb0123c8d
font_02_sfnt_off0000ebb8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBB8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1