Malicious PDF — malware analysis report

Static analysis result for SHA-256 b0b79f3ba95192c9…

MALICIOUS

PDF

70.9 KB Created: 2021-09-27 10:03:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 84c38588e90685206c924c84d809149d SHA-1: d6777bcbf9ce67c23c12d2a686a821fd5d578c90 SHA-256: b0b79f3ba95192c98a578200d6481f80df08c51949a6f479a665d5495b2a0c89
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a large number of embedded URLs, many of which point to compromised WordPress upload directories or disposable hosting. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. The document's structure as a link farm suggests it's designed to lure users to external, potentially harmful, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://wastran.ru/uplcv?utm_term=cover+fire+mod+apk+free+download PDF link annotation
    • https://ncltandatbar.com/home/ncltandat/public_html/dowalumniusa/ckfinder/userfiles/files/vebakomofulonekegevuwemu.pdfIn PDF document text
    • https://doanhnghiepvietnam.org/img_duhoc/files/97511042540.pdfIn PDF document text
    • http://studiosantomauro.it/userfiles/files/samijoworupe.pdfIn PDF document text
    • http://uts.edu.co/portal/app/ckfinder/userfiles/files/17618823881.pdfIn PDF document text
    • http://dorp.pl/userfiles/files/69484059616.pdfIn PDF document text
    • http://in-dapt.com/wp-content/plugins/formcraft/file-upload/server/content/files/16150df8a02917---32502312066.pdfIn PDF document text
    • https://dichvumayphoto.vn/webroot/img/files/39987208880.pdfIn PDF document text
    • https://sacc-la-chaux-de-fonds.ch/fichiers/file/nufufekilitetume.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eaca0f15a1---51131787632.pdfIn PDF document text
    • http://inbjnews.com/data/cheditor/0603/files/gekakukezu.pdfIn PDF document text
    • http://thcsducthang.pgdbactuliem.edu.vn/ckfinder/userfiles/files/42009737073.pdfIn PDF document text
    • https://linardi.ru/files/file/49348808008.pdfIn PDF document text
    • https://wic-net.com/userfiles/file/96767592102.pdfIn PDF document text
    • http://ahrestygz.com/userfiles/files/20210926_234758.pdfIn PDF document text
    • http://dynamic1984.com/user_file/file/53417136738.pdfIn PDF document text
    • http://topp.pl/_topp/file/49152213143.pdfIn PDF document text
    • http://huh.hu/UserFiles/File/40388412907.pdfIn PDF document text
    • http://falconfam.com/ckfinder/userfiles/files/60649084426.pdfIn PDF document text
    • https://atx-stroy.ru/wp-content/plugins/super-forms/uploads/php/files/23b5f23e684aa072b0d9a3365358942e/paxolobotaxipevokowugopor.pdfIn PDF document text
    • http://suachuadienlanhhoaphat.com/hinhanh_fckeditor/file/78366936770.pdfIn PDF document text
    • http://marta-galan.com/files/varios/file/nalivitozazu.pdfIn PDF document text
    • https://recapress.com/ckfinder/userfiles/files/46261882867.pdfIn PDF document text
    • http://hieuchuan.com/upload/files/95507434042.pdfIn PDF document text
    • http://harringtonassociateslaw.com/Test/JabzMedicalBillingService/userfiles/file/16584730253.pdfIn PDF document text
    • https://newtech-utm.pl/userfiles/file/22773591141.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_off0000b4d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4D0 15856 bytes
SHA-256: 7463df8e8b27f9ba8f942facca027b8c49327b57a49734783f11da434c42d9c5
font_01_sfnt_off0000dd41.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD41 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f558.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF558 10668 bytes
SHA-256: 740a484fc806611c1dcfed464b608123ac75374adac94fdabacda1495310a188