Malicious PDF — malware analysis report

Static analysis result for SHA-256 5fcb4a7db6961557…

MALICIOUS

PDF

73.9 KB Created: 2021-09-03 13:22:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 26576816bbc9b59d06146525b74c5f1b SHA-1: 2c3b9c16342ac85ef29d22ef110de9bc664ef598 SHA-256: 5fcb4a7db696155747daabf60a405682cfd5ffe31378caa2e9a34aa759ae0040
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is often used to redirect users to malicious websites or download further payloads. Several heuristics indicate the PDF is part of a link farm, with many URLs pointing to compromised or disposable hosting, suggesting a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://f-okinawa.com/img/tmp/files/47477593847.pdf In PDF document text
    • https://rivaflo-south.in/userfiles/files/penetup.pdfIn PDF document text
    • https://digireg.se/upload/lugomisowotuzij.pdfIn PDF document text
    • http://srihemkuntsahibfgp.org/hemkunt/userfiles/file/99951070113.pdfIn PDF document text
    • https://cantarefides.ro/admin/userfiles/file/fadelefetowenunudesaro.pdfIn PDF document text
    • https://robotics-institute.com/wp-content/plugins/super-forms/uploads/php/files/8t4vmp3kasndojb4avv5bnpum8/kuzoratezibaz.pdfIn PDF document text
    • http://barexkft.hu/userfiles/file/73881452477.pdfIn PDF document text
    • http://stagnesreunion.com/clients/e/ed/ed16748122b3ff8ec97113314e0446c4/File/topaf.pdfIn PDF document text
    • http://xiaohecollege.com/d/files/wisomul.pdfIn PDF document text
    • http://hpmcfamilyreunion1968.com/clients/83891/File/11578813397.pdfIn PDF document text
    • http://biomassasia.net/data_ed/userfiles/file/76971219918.pdfIn PDF document text
    • https://castilloexterior.es/ckfinder/userfiles/files/58623825502.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8728fbdbb6---sogijowenogewa.pdfIn PDF document text
    • http://x-site.by/upload/editor/files/mexer.pdfIn PDF document text
    • http://phutunggiahungoto.com/uploads/files/59097767660.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/gilumibixodipobuxo.pdfIn PDF document text
    • https://www.theoakshealthcare.com/my_content/js/ckfinder/userfiles/files/makakawu.pdfIn PDF document text
    • http://handsonmontessoripk.com/userfiles/files/56875982213.pdfIn PDF document text
    • http://fly.no1-yes.com/userfiles/file/34706148485.pdfIn PDF document text
    • http://absigorta.com/E/file/mepepamitidajedi.pdfIn PDF document text
    • https://ags-car.60km.com/upload/files/gusideveruginesum.pdfIn PDF document text
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fe0e232c63b---34245240875.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=zeta+potential+in+colloid+science+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_off0000bc7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC7E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d490.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD490 17760 bytes
SHA-256: 9b33271656578f18958b0ac2ccd212fb7cc2d3cf96ef35a24e0e994c2a5a525e
font_02_sfnt_off00010251.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10251 10476 bytes
SHA-256: b516e2432e19420271c4eaf105cdc605735f9675b702d53d337b7dcaed78b95e