Malicious PDF — malware analysis report

Static analysis result for SHA-256 20c21d24918f9d0d…

MALICIOUS

PDF

81.4 KB Created: 2021-10-13 14:08:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-03
MD5: 9ac81f46264811d64d7ba018c6dcbb9e SHA-1: 0d11026c3f93c102ae3bf3088b718359858fb402 SHA-256: 20c21d24918f9d0d3a8315c0864498ada0a94eb0e2cd95318f43dfb06102ccc3
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV detection, indicating malicious intent. The document contains an embedded JavaScript stream and numerous external links, many pointing to compromised CMS uploads or disposable hosting, suggesting it functions as a link farm to distribute malicious content or phish for credentials. The presence of JavaScript indicates potential for further exploitation or payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://gzky.cn/dubeite/ckfinder/userfiles/files/20211012_154230.pdf In PDF document text
    • http://thelonerangerfanclub.com/ckfinder/userfiles/files/94194764424.pdfIn PDF document text
    • https://www.shropshirefurniture.co.uk/admin/ckfinder/userfiles/files/benuk.pdfIn PDF document text
    • https://greenlandpark.com/uploads/files/lejivowed.pdfIn PDF document text
    • http://global-leasing-management.com/uf/file/89240598162.pdfIn PDF document text
    • http://ivankotov.ru/img/lib/file/wugodoge.pdfIn PDF document text
    • http://braciszewska-klimek.pl/fck_files/file/rigasefan.pdfIn PDF document text
    • https://tl-systems.hu/files/files/19100075573.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16156c438629f7---78747228897.pdfIn PDF document text
    • http://bukvoznaika.ru/ckfinder/userfiles/files/53077577489.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/16162e4234b601---26514143899.pdfIn PDF document text
    • https://mayxaydungthienlong.com/uploads/files/files/mafobo.pdfIn PDF document text
    • https://www.bankkartya.hu/js/ckfinder/userfiles/files/35864127394.pdfIn PDF document text
    • http://bavlas.lt/ckfinder/userfiles/files/xezofa.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/vf6g92e5k3m7thi4mdh3vhalj5/75615699701.pdfIn PDF document text
    • http://letnipohar.cz/upload/file/naziduduxolilaxizemewi.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/8bcrb3rq6smr6pjedjt4acq8v0/17645315465.pdfIn PDF document text
    • https://netpage.info/userfiles/file/jitujefigubividajitaz.pdfIn PDF document text
    • http://safires.cz/ckfinder/userfiles/files/3833207369.pdfIn PDF document text
    • https://sledovani2.gpshlidac.cz/www/userfiles/files/xovege.pdfIn PDF document text
    • http://koreaseals.com/ckfinder/userfiles/files/poridusus.pdfIn PDF document text
    • http://maudchristan.nl/ckfinder/userfiles/files/tabolelosumovopaw.pdfIn PDF document text
    • http://mkbeauty.vn/luutru/files/30011784528.pdfIn PDF document text
    • http://feedproxy.google.com/~r/MbOu/~3/TSvcnjQ06Jg/uplcv?utm_term=me+and+dupreePDF 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_off0000d7b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7B8 19372 bytes
SHA-256: a10e510b264e2330b03264bb168d621c1128b26e7efedc6ddd2abf92d95346a8
font_01_sfnt_off00010a2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A2D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012243.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12243 9956 bytes
SHA-256: 81fbafe696c9b103986b938510e59a58b203fbbf1d8ba049dc925cf0556be2a1