Malicious PDF — malware analysis report

Static analysis result for SHA-256 721c44d9f8e299a3…

MALICIOUS

PDF

79.3 KB Created: 2021-09-06 01:06:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 9a2a17ed211dbc8af945a2e2f863918e SHA-1: 481f107a6dcf52fe9b528f6f3818f04bd007eb5f SHA-256: 721c44d9f8e299a340446a0fb2623222f9fc4b9fadfaf2c2adff9fc08e81ab3b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to other PDF files hosted on various domains, many of which appear to be disposable or compromised. This structure suggests a link farm designed to lure users into downloading further malicious content or visiting phishing sites. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://ketchas.ru/uplcv?utm_term=baixar+livro+after+5+em+pdf+gratis PDF link annotation
    • http://arcomproltd.com/userfiles/file/77846749759.pdfIn PDF document text
    • http://vitalbafitnessclub.eu/userfiles/files/tugetagerirubosogu.pdfIn PDF document text
    • http://softwarefactory.nl/images/file/ketovuzarinozimamago.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608705862ff35---388220430.pdfIn PDF document text
    • http://boek.se/bilder_umeny/File/garud.pdfIn PDF document text
    • http://drentmedischadvies.nl/uploads/files/wejowinuzagimise.pdfIn PDF document text
    • https://plswa.com/wp-content/plugins/super-forms/uploads/php/files/89eee598a021258d96bcbe30dab1a8e5/lotilu.pdfIn PDF document text
    • https://jakspravnenapsa.cz/userfiles/file/95770488138.pdfIn PDF document text
    • https://discovercefalu.com/_data/images/file/fijukewunopawepezesegep.pdfIn PDF document text
    • http://xn----7sbabaajmdfbk3ddf3azka3b6a2r.xn--p1ai/ckfinder/userfiles/files/fasufefigitadonalaje.pdfIn PDF document text
    • http://mulroyenvironmental.ie/userfiles/file/dilare.pdfIn PDF document text
    • http://sobinco.cz/ckfinder/userfiles/files/xotexiw.pdfIn PDF document text
    • http://bakefruit.com/uploads/files/202108141817194374.pdfIn PDF document text
    • http://www.peopleoftheheath.com/wp-content/plugins/formcraft/file-upload/server/content/files/160babf22a6029---3460238722.pdfIn PDF document text
    • http://artdealer.vn/upload/fckimagesfile/797e7e6749c2881ecac36183f2db5b17.pdfIn PDF document text
    • https://thediamangroup.com/_images/files/joluj.pdfIn PDF document text
    • http://secretinvitation.net/images/files/6342737889.pdfIn PDF document text
    • https://www.micd.edu.np/ckfinder/userfiles/files/40551021188.pdfIn PDF document text
    • https://pilotcenter.gr/wp-content/plugins/super-forms/uploads/php/files/d0phnmvlap1vnij1dph4elm3gi/fodinutobafidage.pdfIn PDF document text
    • https://sf-tfi-pgu.uz/wp-content/plugins/super-forms/uploads/php/files/07a59ebb1ca3ee088657a8f874817102/23844539380.pdfIn PDF document text
    • http://sapaethnic.com/webroot/img/files/sisitufobapaxumowegaje.pdfIn PDF document text
    • https://linhngapt.vn/upload/files/77338238881.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_off0000ce11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE11 18576 bytes
SHA-256: 2dd76e346b94041d6665c552bbce46772e75fc0e55cb16db0d629bc7da2af404
font_01_sfnt_off0000fef0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEF0 11092 bytes
SHA-256: a9a0a4a6fee27f5e4112f509481c5f564121e7c804c65620129b67f04c32c93f
font_02_sfnt_off000118ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118BA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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