Malicious PDF — malware analysis report

Static analysis result for SHA-256 d666d532ee9c7171…

MALICIOUS

PDF

78.9 KB Created: 2021-09-05 11:56:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: f7ea5f5eed6c8a285a5bb12ae0d8f4dc SHA-1: 36d59c4fea59555fa4472b7a67069890f08b7725 SHA-256: d666d532ee9c717118a151613b653debd3bb82b69386348f5475c988ec306b20
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm with numerous URLs pointing to various domains, many of which are hosted on compromised WordPress sites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the structure and URL patterns are consistent with a malicious PDF designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://salinahighschool1968.com/clients/3/33/33fcb9b832a528c934b1ac42c6b88a99/File/pinujo.pdf In PDF document text
    • http://888chji.com/userfiles/files/27547784171.pdfIn PDF document text
    • http://lumieretvie.com/userfiles/file/25897399412.pdfIn PDF document text
    • http://nakakinpump.kr/fckeditor/upload/file/33209388270.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-6-19/20210619111509605342.pdfIn PDF document text
    • http://broadviewlibrary.org/uploaded_bvlib/file/newibezolulokuwuxupizak.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3cf5ebc787---palijepofi.pdfIn PDF document text
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16092dc774bfd7---zapono.pdfIn PDF document text
    • https://ashasuchikala.com/ckfinder/userfiles/files/10719424314.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bf14f5ebe5a---91509068883.pdfIn PDF document text
    • https://daleel.global/wp-content/plugins/super-forms/uploads/php/files/e98ibvut3jl6817maoe8mlc8ri/11072300681.pdfIn PDF document text
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/b65209da88898130f9d6cff12840add0/2573730054.pdfIn PDF document text
    • http://ewhamd.net/upFiles/ckeditor/files/45706636931.pdfIn PDF document text
    • http://murphysbeads.com/clients/54316/File/86919132548.pdfIn PDF document text
    • http://rotarycochinharbour.org/ci/userfiles/files/95280601917.pdfIn PDF document text
    • http://sushistoryus.com/uploads/files/fopexegopufofifin.pdfIn PDF document text
    • http://studioingegneriavaragnolo.com/userfiles/files/fubogabo.pdfIn PDF document text
    • http://savalis.ru/userfiles/file/5871476673.pdfIn PDF document text
    • http://grgct.com/ckfinder/userfiles/files/4020631446.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/160779cfa85f97---82580055716.pdfIn PDF document text
    • http://utpcomp.ru/uploads/files/gudosobexurorenazajasode.pdfIn PDF document text
    • http://wanyuantemple.tw/userfiles/file/89955657204.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083653e81b12---28155965472.pdfIn PDF document text
    • https://truongthanhco.vn/webroot/img/files/pukopidavaxesawituv.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-5-22/20210522055943359229.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=intermezzo+from+cavalleria+rusticana+piano+pdfPDF 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_off0000cfb2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFB2 16956 bytes
SHA-256: 3f43ea940e6ddcb27832ad11311e1ac2051ea6a308bb2c508fba783b08512ee1
font_01_sfnt_off0000fbea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBEA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011401.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11401 10960 bytes
SHA-256: 8c837a13ab1528ee848c847ea12b192952052a7d2cef6b793ea8ba8743fde1f3