Malicious PDF — malware analysis report

Static analysis result for SHA-256 8728a93b8166b6e2…

MALICIOUS

PDF

84.9 KB Created: 2021-10-19 17:45:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: ccb5f7b5f4416ec915152d6d70553a7d SHA-1: a04c0dff2d0ec1152353ac063288fbe09a04854f SHA-256: 8728a93b8166b6e2858fe5f6bcc187d3c66dc19b3b53e69e47b4a19175654a82
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the nature of the heuristics strongly suggest this PDF is part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 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://inwebjor.ru/uplcv?utm_term=evaluation+pr%C3%A9sent+de+l%27indicatif+cm2+%C3%A0+imprimer PDF link annotation
    • https://mudrun.com/home/mud/public_html/ckfinder/userfiles/files/xupofane.pdfIn PDF document text
    • http://conelser.hu/fck_uploads/file/duveg.pdfIn PDF document text
    • http://dongkoo.com/uploads/editor/files/walobu.pdfIn PDF document text
    • http://birnagarcollege.in/userfiles/file/26690193577.pdfIn PDF document text
    • https://maxlinder.com/admin/assets/ckfinder/userfiles/files/23239757068.pdfIn PDF document text
    • http://effekt-film.de/files/file/kafiparafojifugojaw.pdfIn PDF document text
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16130854de868d---57039739911.pdfIn PDF document text
    • https://aslimitada.com/userfiles/file/supix.pdfIn PDF document text
    • http://miyisz.com/mingyi/images/userfiles/file/wexaneferumuxixujepo.pdfIn PDF document text
    • http://gk-eventus.ru/admin/ckfinder/userfiles/files/jetilamojodabuzenexifoxuk.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/1616aca09c5c14---48445403584.pdfIn PDF document text
    • http://warmistore.com/userfiles/file/ledibibokimif.pdfIn PDF document text
    • http://pate4me.com/userfiles/file/wulogefijijasen.pdfIn PDF document text
    • http://xn--b1agjlwjc3g.xn--p1ai/ckfinder/userfiles/files/38104826204.pdfIn PDF document text
    • https://tolgyesvolgy.hu/userfiles/file/67904047931.pdfIn PDF document text
    • http://rkmaster.ru/uploads/files/22918739019.pdfIn PDF document text
    • http://newgatedesign.com/Images_upload/files/42471838165.pdfIn PDF document text
    • http://asupuro.com/upload/save_image/files/12814270722.pdfIn PDF document text
    • http://beverleyannes.net/home/beverley/public_html/ckfinder/userfiles/files/9972579421.pdfIn PDF document text
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1616e49b4700ae---28605200227.pdfIn PDF document text
    • http://2safe4u.cz/UserFiles/File/loxenedezu.pdfIn PDF document text
    • http://tangiahoang.com/skinkorea/Images_upload/files/zipud.pdfIn PDF document text
    • https://ural-aiti.ru/admin/ckfinder/userfiles/files/72821046793.pdfIn PDF document text
    • https://elnativocoffee.com/silver/upload/files/limuziku.pdfIn PDF document text
    • https://blueparadise.pl/userfiles/file/24464486856.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_off0000dc80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC80 11420 bytes
SHA-256: 008d6f1da89bedb0204f5c99890d379d6f0d20f70714c090b5f798940d20daf1
font_01_sfnt_off0000f6d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6D8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010eea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EEA 20664 bytes
SHA-256: 13af4031916a6ec0612e16d9cd21c2110088c6d3e14f307370fb163b73e6bc21