Malicious PDF — malware analysis report

Static analysis result for SHA-256 82a3351368672625…

MALICIOUS

PDF

83.8 KB Created: 2021-09-03 21:58:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 51e38b77d4e010f65d7306537db63ab6 SHA-1: 503a1430aa888485610271bc3d787830d6c6d819 SHA-256: 82a33513686726259a509c6ebb648c09ac386d1ecdbab1ac926d5b3c91d98b51
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple heuristics indicating it is a link farm, with many URLs pointing to potentially compromised websites or disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO abuse. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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 http://glamour-nsk.ru/ckfinder/userfiles/files/dobosisegamijiguvilo.pdf In PDF document text
    • https://eltonltd.ru/sites/default/files/uploads/22352554060.pdfIn PDF document text
    • http://belean.pl/userfiles/file/gimukijunopo.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160f280a4007fd---kuvunolugasefavitoruk.pdfIn PDF document text
    • http://stonestudio.pl/files/upload/file/tuwezemamobol.pdfIn PDF document text
    • http://mijn-nederland.nl/userfiles/file/25616340397.pdfIn PDF document text
    • http://atthaya.com/file_media/file_image/file/29917271304.pdfIn PDF document text
    • https://ambient-interier.cz/files/files/44951663363.pdfIn PDF document text
    • http://hondatayho.vn/images/ckeditor/files/busaxirijelitaxekul.pdfIn PDF document text
    • https://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/b30fa682f023d9237b32f505e44ac9f9/69252738635.pdfIn PDF document text
    • https://olivierdaulte.com/ckfinder/userfiles/files/51017593964.pdfIn PDF document text
    • http://cec-intl.ru/app/webroot/files/file/44962401241.pdfIn PDF document text
    • http://vizit-k.net/uploads/editor/files/37835362091.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a1517ea1d2---fewidijuzijepemel.pdfIn PDF document text
    • http://nhs1966reunion.com/clients/1/1c/1ca8f1639ee69cd7806809ed3bcda9bb/File/kemoxinozoje.pdfIn PDF document text
    • http://titusrelay.com/clients/e/ef/ef304ccc03541e9e6382bef5f13b0a7d/File/79007794314.pdfIn PDF document text
    • https://airbays.com/userfiles/file/ruruzegumopabo.pdfIn PDF document text
    • http://allprintusa.com/admin/images/file/50563833732.pdfIn PDF document text
    • https://cfi-registration.org/buzzboxgift/img/userfiles/files/11754907198.pdfIn PDF document text
    • http://studiocalderini.it/userfiles/files/4889102008.pdfIn PDF document text
    • https://mygoaltv.com/ipp/images/uploads/files/gimesanezun.pdfIn PDF document text
    • http://oticonshop.net/ckfinder/userfiles/files/75605958393.pdfIn PDF document text
    • http://bafiti.com/sklep/userfiles/file/tabubevutarug.pdfIn PDF document text
    • https://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/3ae1876222815b28dff413180ff5481e/13103689189.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d8ee35bb007---25690507245.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=journal+phytochemical+screening+pdfPDF link annotation
    • https://mediaget.com/userfiles/files/lawowomibakevodijiza.pdfIn 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_off0000dda9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDA9 11272 bytes
SHA-256: 9415430cefce18b9de846833cbb558b3fe26db81c83cc2cdcb67ecbb3d6cb3cd
font_01_sfnt_off0000f7bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7BD 18824 bytes
SHA-256: 6e862c951e8b2399ea0bc8ae16be586d8790257e9702c96b9124404548a2eb78
font_02_sfnt_off0001290f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1290F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1