Malicious PDF — malware analysis report

Static analysis result for SHA-256 16c55b8e733ead29…

MALICIOUS

PDF

83.6 KB Created: 2021-09-06 19:56:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 7e9031c801ead4039b03ab250988968a SHA-1: 567a677f4f801d5c40faa3d5fc3a04c884a5f2ac SHA-256: 16c55b8e733ead291e85a5cf6ed1b36b355fc68f357a37158203d6893804c09c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous embedded URLs, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The document body is heavily obfuscated and unreadable, but the presence of these links strongly indicates a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://olympicwroclaw.pl/zdjecia/fck/file/verodotukinowesa.pdf In PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/cde64c5888282e31454e53ff10ca562b/51170342773.pdfIn PDF document text
    • https://menu2uplus.com/images/file/98978522213.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160f4286f0d62d---71527433735.pdfIn PDF document text
    • http://networkinglikepro.com/ckfinder/userfiles/files/96889383247.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/kf5159pb5djs11j949eijjk742/67990923100.pdfIn PDF document text
    • http://ip-golubev.ru/ckfinder/userfiles/files/mokazukitiziga.pdfIn PDF document text
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/160dc0747aa68b---tewuletezawazeruwejekes.pdfIn PDF document text
    • http://i-harmonics.com/upload/files/remixixolusibalowu.pdfIn PDF document text
    • http://hoaisonland.vn/upload/files/nazux.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098bd4aa100f---lulune.pdfIn PDF document text
    • https://sailstudy.in/ckfinder/userfiles/files/50319378466.pdfIn PDF document text
    • http://ajtoablakcentrum.com/_user/file/81310273978.pdfIn PDF document text
    • http://ovartec.com/wp-content/plugins/formcraft/file-upload/server/content/files/16126a64e4c13b---vilotumit.pdfIn PDF document text
    • http://tele-video.ru/upload/files/32453239414.pdfIn PDF document text
    • http://terralis.net/catalogue_dynamique/file/9555611341.pdfIn PDF document text
    • http://plkorea77.com/ckupload/files/49308370558.pdfIn PDF document text
    • https://siahotel.com/userfiles/files/41872480726.pdfIn PDF document text
    • http://rentaruedas.com/files/others/32685878104.pdfIn PDF document text
    • https://natyabio.com/uploadfiles/82130674749.pdfIn PDF document text
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/160f46821cf390---86888137758.pdfIn PDF document text
    • http://staging.impactredevelopment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608447111be0f---8123695452.pdfIn PDF document text
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/8b47b262b28cc002358b2827591550cc/67452428452.pdfIn PDF document text
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/khsafg9r7n1macu78n355c34ov/29308691137.pdfIn PDF document text
    • https://nowbali.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/160a71fe17ae6f---vizedofaxogabuzulibiken.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=incluir+assinatura+digital+em+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_off0000e141.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE141 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f953.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF953 18188 bytes
SHA-256: 2ccf393a27664809efb7c1508f3f4b5fc427bfab076d2e17128c2870386dbe88
font_02_sfnt_off000127c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127C0 10896 bytes
SHA-256: 491bd3669f3657a7f89f04e0da7ab1bd5984214a9b5ad55c7172c1e70feafe90