Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4de8c90a7f79190…

MALICIOUS

PDF

87.0 KB Created: 2021-07-13 08:14:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: fa4274f4f8b88dc83d3b7d0a15c3aa78 SHA-1: 08cd8f8ff60a838277aff85b1beef387f210a368 SHA-256: b4de8c90a7f791902c06286c3160226b6472b1739f1f743ffb5b8b57423fc01f
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites using formcraft plugins for file uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. The presence of multiple distinct hosts and the structure suggest a link farm designed to obscure the ultimate destination or leverage compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/16071d7941fe65---wevusubumafufigoxese.pdf In PDF document text
    • http://hanasushimenifee.com/uploads/files/vekoki.pdfIn PDF document text
    • http://changwontour.kr/FileData/ckfinder/files/20210707_3810E1222984519E.pdfIn PDF document text
    • https://ascii.tn/web/cgi/file/72484543272.pdfIn PDF document text
    • http://sns.hu/_user/file/kesuzibewapen.pdfIn PDF document text
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/oh3j1ccl1g3nvcqbiijoslcnm1/pesinejuwezuximiw.pdfIn PDF document text
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a783ad5e1f---dujekafufozegafolurateva.pdfIn PDF document text
    • https://tese.in/ckfinder/userfiles/files/xuleregiz.pdfIn PDF document text
    • https://iphonerepairservice.nl/app/webroot/files/userfiles/files/deditafogitipojunumuj.pdfIn PDF document text
    • https://bonacorsi.it/file/13446653178.pdfIn PDF document text
    • http://csc-028.com/userfiles/file/20210622192204_luuzj7.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/160e94afff3f27---6040200432.pdfIn PDF document text
    • https://angkortaxiservice.com/userfiles/file/lotigakodilevudem.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac793138056---tojorixok.pdfIn PDF document text
    • https://infiniteprospects.com/FCKeditor/file/88048754288.pdfIn PDF document text
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077860d78e2d---43508441177.pdfIn PDF document text
    • https://detectiveoffice.net/userfiles/file/mefaguxumotobosekigek.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608e60ae800f6---5640352786.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e315b229880---fupasuxubadunoxo.pdfIn PDF document text
    • http://aiswaryamatrimonials.com/fck_uploads/file/sopowupitujuwekijola.pdfIn PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/vn3hf1grjjjut3s55no2rv9eg4/wijurarizapile.pdfIn PDF document text
    • http://maxkbm.com/clients/2/28/28fcaa936e2ecbeb6c9a97ea0f1ab253/File/29618338464.pdfIn PDF document text
    • https://istanajp2.com/contents//files/vototezaloxawivabasibo.pdfIn PDF document text
    • https://djhelaly.com/wp-content/plugins/super-forms/uploads/php/files/f591741d06e466ddab8bffcb04b8a38e/dewibigesot.pdfIn PDF document text
    • http://xn----7sbabaajmdfbk3ddf3azka3b6a2r.xn--p1ai/ckfinder/userfiles/files/12570863807.pdfIn PDF document text
    • http://smartvoicecom.com/userfiles/6945667220.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/3gcmt8upqu5u8511dv3a3vjg9c/58635469433.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=social+issues+affecting+youthPDF 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_off0000f0cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0CD 10804 bytes
SHA-256: 1bba771c41600be5fc387701c7a9e9eedc93b74cb124532e7a9ac0bd28950b28
font_01_sfnt_off000109a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109A1 17256 bytes
SHA-256: 633e7434363a496b95858d59b9ec5820f64255b19e7edd2e6b65f3b4a7cbf35c
font_02_sfnt_off000136a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136A8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1