Malicious PDF — malware analysis report

Static analysis result for SHA-256 53b5e7b9500b5015…

MALICIOUS

PDF

78.7 KB Created: 2021-09-07 09:25:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: fc6a0b472cc0e98eed61b446777c2922 SHA-1: 894e59206e564265bedc816bce2277f0e79b0724 SHA-256: 53b5e7b9500b5015d4da364d877033e622d3ade3dc8106e4062b3003dd89541f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous links, many pointing to compromised CMS uploads and disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://sammycar.ch/sammy/sites/default/sammyfiles/newsletterfile/4862405418.pdf In PDF document text
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/6i70o4tc9vftcbrojk0lgabgm4/27357734743.pdfIn PDF document text
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/6355bfc487301e50581e8ad18d82b871/87611551967.pdfIn PDF document text
    • http://malopolskiszlakwinny.pl/upload/File/tesoxed.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160aa21fcb6a15---13543694408.pdfIn PDF document text
    • http://cicm2015.mist.ac.bd/app/webroot/ckfinder/userfiles/files/91037356638.pdfIn PDF document text
    • http://szentimresiklos.hu/upload/file/23690915547.pdfIn PDF document text
    • http://hollandunitedreunion.com/clients/5/52/52f3fdf721cdccceb566e47094f1d9de/File/1864868250.pdfIn PDF document text
    • http://bacsionline.net/userfiles/file/9664545540.pdfIn PDF document text
    • https://belloverde.net/emailer/file/xiberizetutejasonewuwe.pdfIn PDF document text
    • http://vincentpopetutoring.com/clients/d/dd/dd6b7bcf94cac99d3bed97cf8166637b/File/10083016204.pdfIn PDF document text
    • https://vestol.bg/files/file/kunuzijipogegijage.pdfIn PDF document text
    • http://rasciindia.com/firetech/ckupload/files/52273690790.pdfIn PDF document text
    • https://bayramkaracabeton.com/images/Media/files/73989627092.pdfIn PDF document text
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/eba699d6a6ac08920a0e583a22f840d1/mubijavovezimum.pdfIn PDF document text
    • https://dcimx.com/files/29452641217.pdfIn PDF document text
    • http://onnetsolution.in/userfiles/file/66927755169.pdfIn PDF document text
    • http://yuha.be/_files/file/xelisife.pdfIn PDF document text
    • http://www.contectrade.hu/fckfiles/file/bavozur.pdfIn PDF document text
    • https://thanaclusterwestgate.leaddeehub.com/userfiles/files/rezabogepalamigezanesof.pdfIn PDF document text
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607585e2d0d2c---binasotodonesinovifajiwil.pdfIn PDF document text
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/6f58c47d2814abd357770bb01f7ee923/zonok.pdfIn PDF document text
    • http://timeyear-v.com/userfiles/file/41229370991.pdfIn PDF document text
    • https://xuanhongkhang.com/upload/files/memajikilepovaxili.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=revit+mep+certification+exam+questions+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_off0000c652.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC652 20148 bytes
SHA-256: 35dfb24d4c7847c203ab1eec5a6434687e6f1de555a3838575c19708d5786aba
font_01_sfnt_off0000fb24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB24 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001133b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1133B 11196 bytes
SHA-256: fc452fbfd02f9226c8a1274149401ec75945753295652c54ff27ffcc4f81709a