Malicious PDF — malware analysis report

Static analysis result for SHA-256 b664bdac66f60cc9…

MALICIOUS

PDF

91.4 KB Created: 2021-08-03 02:59:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 59d8f24bc830cbb841cff9446e04be07 SHA-1: 04b0d524f317bb31854fc4de93c2f064f93421de SHA-256: b664bdac66f60cc9184dd520bdeaf1d59798a9a111da804282350fd3e273a3dc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS upload storage and disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and link farm behavior are consistent with techniques used to host malicious content or redirect to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.winsum.frl/ckfinder/userfiles/files/bunemuse.pdf In PDF document text
    • https://netiko.ge/img/Data/file/lewumakituba.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b6146c40321---fujuxojisavitutelixivif.pdfIn PDF document text
    • https://implant-drill.com/userfiles/file/tabonifo.pdfIn PDF document text
    • http://www.sictombbi.fr/ckfinder/userfiles/files/lalilewo.pdfIn PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cd358d7c0a---xegafefibo.pdfIn PDF document text
    • http://wksystems.net/HotelEstimator/userfiles/file/gokuxatilulutugixovawide.pdfIn PDF document text
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076523dd04c8---vovoxolufudajegus.pdfIn PDF document text
    • https://pingthye.com/userfiles/files/8349402491.pdfIn PDF document text
    • http://odpadykj.cz/UserFiles/File/76462816997.pdfIn PDF document text
    • https://rux-thai.com/ckfinder/userfiles/files/47000266380.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/16082f0db3791c---94810962064.pdfIn PDF document text
    • https://alternativecarrepair.com/userfiles/file/50550256189.pdfIn PDF document text
    • https://www.mnogotrop.com/ckfinder/userfiles/files/18933013647.pdfIn PDF document text
    • http://solee.cn/ckfinder/userfiles/files/64855158862.pdfIn PDF document text
    • https://motelandratecuci.ro/userfiles/file/69332604148.pdfIn PDF document text
    • http://aliceinformaticasrl.com/user/pages/44172422442.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/1ho1j4ejqce5imqpsnih6810an/minuzupazokadilesim.pdfIn PDF document text
    • http://www.siscbolivia.com/admin/uploaded/fck/file/sujadafetagawapux.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c53684a3368---sutepekedodanojofubita.pdfIn PDF document text
    • http://graphicyazd.com/ckfinder/userfiles/files/57119505609.pdfIn PDF document text
    • https://auf.vn/wp-content/plugins/super-forms/uploads/php/files/tpfnck8kenrk6i4rn0qusdfef4/51362912140.pdfIn PDF document text
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/595883ba625cac352126492721e40be2/21497200865.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e3837e2c7cb---puturevobi.pdfIn PDF document text
    • https://ferado.vn/userfiles/file/93997714876.pdfIn PDF document text
    • https://www.kbstephens.com/wp-content/plugins/super-forms/uploads/php/files/dbb7f308f62332e544c07c33af57f26c/waxugatogetobetumezanewun.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=python+tkinter+tutorialspoint+pdfPDF link annotation
    • http://www.tutorialspoint.com/python/python_gui_programming.htmIn 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_off0000fdac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDAC 10900 bytes
SHA-256: a577373725f03fd7e49a1608f5fa6f4d909458a1deafc1a70c4a2213f3ae0b97
font_01_sfnt_off000116e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116E5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012ef7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EF7 18676 bytes
SHA-256: dd481cfa4d2784c6dfea984a4dca6b267fd9ccad49d458ae97e1ca08a170645f