Malicious PDF — malware analysis report

Static analysis result for SHA-256 55b630eb21b6577f…

MALICIOUS

PDF

83.5 KB Created: 2021-08-24 00:05:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: a0624480e36bafbad0431bc0da2ce4d5 SHA-1: e82812b0e15cd759e21a9249353c3c506fd7f3e4 SHA-256: 55b630eb21b6577f8bc6cfde6a384faa3ab966d7aa66576b07eb619929f47586
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It functions as a link farm, pointing to numerous URLs, some of which are hosted on compromised CMS upload directories. The presence of these links suggests an attempt to redirect users to malicious content or phishing sites, likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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://cosalesrep.com/wp-content/plugins/super-forms/uploads/php/files/69c1d57d37e84995fc9c5472bfecd4e3/34169820171.pdf In PDF document text
    • http://hi-reid-solutions.com/wp-content/plugins/super-forms/uploads/php/files/89c00345b0dc30ee29ff1af3f0598a60/kedenenusopi.pdfIn PDF document text
    • https://bruceautoservice.com/files/file/12480505163.pdfIn PDF document text
    • http://michellesmithscott.com/clients/36670/File/tirodadutinuwedoruxuzuji.pdfIn PDF document text
    • http://jocoseatee.com/userfiles/files/80875453186.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/a2d6efe9cd43688b03365418f6d902b9/melulajivuv.pdfIn PDF document text
    • http://blesk-stroy.ru/userfiles/files/dogobubukejaratu.pdfIn PDF document text
    • http://www.insight-assessment.com/ckfinder/userfiles/files/noresofawijopot.pdfIn PDF document text
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/ps9cfh8o9npnpjoeo05gsmoc8l/28327505298.pdfIn PDF document text
    • http://megalaserasia.com/upload///dosiwuve.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606fb56442d2f---7550479077.pdfIn PDF document text
    • https://holocaustresearch.pl/nowy/photo/file/netijetora.pdfIn PDF document text
    • https://rcot.org/userfiles/file/73111236544.pdfIn PDF document text
    • https://shotclock.ca/wp-content/plugins/super-forms/uploads/php/files/141a6776a3e993cfe1e2b001db7ce314/93175528938.pdfIn PDF document text
    • http://shmountaineering.co.uk/wp-content/plugins/super-forms/uploads/php/files/pn56ld4u9rcp943it2ut3pb4i2/35736197468.pdfIn PDF document text
    • https://bem-sa.com/img/file/disomakozigisebizowasoje.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160faa75cdf6c6---78039681485.pdfIn PDF document text
    • http://christembassydocklands.org/wp-content/plugins/super-forms/uploads/php/files/d7df5fd35b6d31b45ac6c708f5a98f7c/bopaxu.pdfIn PDF document text
    • http://nagyberki.hu/sites/default/files/fck_uploads/file/94586242677.pdfIn PDF document text
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f9aae5c5fa5---sesabisibo.pdfIn PDF document text
    • https://bleikss.com/userfiles/file/93724100582.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/987f67210b5a622da902cce2b9d58ea9/jigamupaxowotujisewepesaj.pdfIn PDF document text
    • http://christopherdallo.com/file/lexeru.pdfIn PDF document text
    • https://belgradenightlife.info/wp-content/plugins/super-forms/uploads/php/files/r9kt9f7lvvt026728psuh1k77n/jibofotiwaximikugefev.pdfIn PDF document text
    • https://coastalholidayproperty.com/ckfinder/userfiles/files/nutowovunimibotivo.pdfIn PDF document text
    • http://opakowania-loga.pl/zdjecia/fotki/file/93238838067.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160836756cabac---makawitapeninuku.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=how+much+precum+is+needed+to+get+pregnantPDF 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_off0000e0da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0DA 17340 bytes
SHA-256: 58253f5f07985daac8bb12cfa6f142ad717f9999d20dfcc7da27d4f89fd3a9d0
font_01_sfnt_off00010e5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E5C 11092 bytes
SHA-256: 2fea21052abc66e0da6cfa22e16fddb86b8758b69e95ec22cb56671848bbb11b
font_02_sfnt_off000127e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1