Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c91950453ef5578…

MALICIOUS

PDF

71.8 KB Created: 2021-10-06 01:32:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 12e4cf596bb8be8e077d07210c82a529 SHA-1: 21202f188f02d65ccb259084bf881674942ee929 SHA-256: 4c91950453ef55789a0b76d427a5f776e896b9305ea2aca0c99732eeef2c3b51
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is a PDF file identified as malicious by ML classifiers and ClamAV. It contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm designed to distribute further malicious content or facilitate phishing. 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 0.9161

Heuristics 5

  • 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
  • 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://www.xpresswedding.com/wp-content/plugins/formcraft/file-upload/server/content/files/16153642493a0a---83839823237.pdf In PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1615633f8771f1---giliwotugosejifujonilum.pdfIn PDF document text
    • http://votejoedestefano.com/editorData/file/jezaxusu.pdfIn PDF document text
    • http://wakabaeducation.com/userfiles/file/83900730178.pdfIn PDF document text
    • https://lux-ride.com/home/u4-6pzgszajsb5u/www/lux-ride.com/public_html/ckeditortest_WORKING/ckfinder/userfiles/files/nubigilenefaku.pdfIn PDF document text
    • http://honmamon-s.com/img_seminar/userfiles/file/45370405409.pdfIn PDF document text
    • http://ipllaser.in/uploads/92585757332.pdfIn PDF document text
    • http://residenzaeden-albisola.com/userfiles/files/mepitukodovisewafo.pdfIn PDF document text
    • http://sonnenheizungen.ch/fckeditor/editor/images/file/sagoniro.pdfIn PDF document text
    • https://tmtteks.com/files/10306391864.pdfIn PDF document text
    • http://aotem.com/data/home/qxu1780220113/htdocs/uploadfile/files/80851553244.pdfIn PDF document text
    • https://successstudio.net/userfiles/file/rizijebufim.pdfIn PDF document text
    • https://ostrichtours.com/ckfinder/userfiles/files/62820898751.pdfIn PDF document text
    • http://amkchem.com/upload/files/10572816303.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139b4fcce43a---27665910556.pdfIn PDF document text
    • http://hftyby.com/upload_fck/file/2021-9-21/20210921091756483731.pdfIn PDF document text
    • http://vuason.vn/upload/files/bapefejodirumamivisivi.pdfIn PDF document text
    • http://glina-master.ru/admin/ckfinder/userfiles/files/xujagered.pdfIn PDF document text
    • https://dtd.com.pk/ckfinder/userfiles/files/23388780731.pdfIn PDF document text
    • http://dentali.cz/files/files/59423227855.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/16134482983be6---teguruv.pdfIn PDF document text
    • http://lasermedia.cn/userfiles/file/wakawetivedajadedixofob.pdfIn PDF document text
    • http://caytrong.vn/Images_upload/files/45085141445.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/2fcf1cce3acfd633103398ce68a1b34a/24403680665.pdfIn PDF document text
    • http://sea-cruise.ru/ckfinder/userfiles/files/vutavutidowisaroranobebad.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=a+smarter+way+to+learn+javascript+pdf+free+downloadPDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f23f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF23F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010a56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A56 11156 bytes
SHA-256: 0134bf32d8f1f67ddefdf2097517f5d9c2543705ceb85db62f70abc77af21cfc