Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d8bd2b8e893fe42…

MALICIOUS

PDF

87.5 KB Created: 2021-09-01 22:45:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 4e365c886524d1ea4fd274a74b3f9084 SHA-1: 74d573814325d5eb0309f2c34651d459436e8ca2 SHA-256: 4d8bd2b8e893fe4228387d6eb5eb9f3b0ee9d73a859022ccce26fbd175c84c6f
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, with a high risk score. It contains numerous links pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution scheme. The embedded URLs and link farm structure indicate an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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 http://szyuangang.com/UserFiles/file///bovuwisumixikufezopoda.pdf In PDF document text
    • http://sunil.kr/uploadfile/fckeditor/file/56587708746.pdfIn PDF document text
    • http://tapestry.cz/images/file/files/75287789405.pdfIn PDF document text
    • http://kursadowicz.pl/Upload/file/32765099882.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609100b5eafc2---95653312762.pdfIn PDF document text
    • http://creatinglifeoptions.com/userfiles/files/30430332941.pdfIn PDF document text
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files//lunifaso.pdfIn PDF document text
    • http://www.zopfitravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c31e23130d0---limujodos.pdfIn PDF document text
    • http://avvocato-callegaro.it/public/file/76262693742.pdfIn PDF document text
    • http://geoplan.su/userfiles/file/zowedawexarumiku.pdfIn PDF document text
    • http://uco-kampen.com/media/files/jetos.pdfIn PDF document text
    • http://xnucleus.com/members/member_images/files/lodebupafix.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/fhrnfnucse39jo0f53s78l9du5/nujomiloko.pdfIn PDF document text
    • https://medius.sk/userfiles/file/78236763151.pdfIn PDF document text
    • http://arndt-fahrschule.de/userfiles/file/29960464447.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160f12518144e6---83565204339.pdfIn PDF document text
    • https://burmesecatclub.nz/wp-content/plugins/super-forms/uploads/php/files/b545990d206fd2aa6d6597d988388464/bobulobuzoteluzodasuvoja.pdfIn PDF document text
    • http://bidwoodmachine.com/d/files/gopinamoxoraveno.pdfIn PDF document text
    • http://karpatskiles.ru/store/files/6974729307.pdfIn PDF document text
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/23201646639727df06890ae52cc9f4b4/50873797850.pdfIn PDF document text
    • http://cokhitienvuong.com/uploads/files/rabenorameresiwaserug.pdfIn PDF document text
    • http://assotechne.eu/userfiles/files/vivugitapif.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=how+to+pair+android+with+airpodsPDF 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_off0000f40b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF40B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010c1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C1D 17236 bytes
SHA-256: 8b8f2d3ceff4945ec872f0e97c591d2e2b9204d54a387dd3442b4498b43423df
font_02_sfnt_off000138b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x138B2 10388 bytes
SHA-256: 05ed0d967b896848fcdfd6fe596f4e93e3d8b447cba510ca42e4c70fa50a5098