Malicious PDF — malware analysis report

Static analysis result for SHA-256 b678c3839cf6fe7e…

MALICIOUS

PDF

81.2 KB Created: 2021-09-04 03:24:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e40b0aca53bed7c6524835650706e88f SHA-1: 029bc4e7b1a768cf41e9d0b2a5f2d27f1a83cb6d SHA-256: b678c3839cf6fe7e25d6e73ff09aa63f6bf276b39c1c9298b4bae188ab21b451
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically identified as a phishing trojan. It contains a large number of embedded URLs, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. While no scripts were explicitly extracted, the PDF structure and URL patterns are indicative of a phishing or SEO manipulation scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://curewelldiabetes.com/userfiles/file/majibuzesefoxa.pdf In PDF document text
    • http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/7cbe8e4c6998ca8b88abb6bda39d359f/81597189926.pdfIn PDF document text
    • https://ajur.rest/uploads/userfiles/file/82890365159.pdfIn PDF document text
    • http://www.korayozelguvenlik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bd501151cd---fogesaju.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088b30c15a40---vukutebet.pdfIn PDF document text
    • http://mwbright.com/upload_fck/file/2021-9-3/20210903040859471631.pdfIn PDF document text
    • https://pragatitic.org/ckfinder/userfiles/files/81511992429.pdfIn PDF document text
    • http://mfcpavpos.ru/file/pexexibexu.pdfIn PDF document text
    • http://dichvuhangngay.vn/uploads/image/files/vosufosiduroxu.pdfIn PDF document text
    • http://epmachine.ru/d/files/jozegamizawuliwobo.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/l3h8krksv6v0tpj3t36v8pul61/16716807011.pdfIn PDF document text
    • https://fullmagicweekend.com/ckfinder/userfiles/files/7163462340.pdfIn PDF document text
    • http://prattsofdouds.com/clients/d/d8/d85aab9f4bcbae69c8358f7a9990a0b1/File/82772343301.pdfIn PDF document text
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a893f6a77f---raninenutedesafi.pdfIn PDF document text
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/v0fvo83oio7nf8nn825bp6lon1/9480457395.pdfIn PDF document text
    • http://wilkinsconnection.com/clients/9/94/94ba1e7d864c5c8af3bb481f5f9f31de/File/14180888956.pdfIn PDF document text
    • http://www.aportecnica.com/imagenes/editor/file/venelalade.pdfIn PDF document text
    • https://louvre.lv/res/wysiwyg/file/muwulojazale.pdfIn PDF document text
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bad82c2571f---gururirutigakeliluxu.pdfIn PDF document text
    • https://rpitrade.com/ckfinder/userfiles/files/34178476347.pdfIn PDF document text
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a02670ca294---8162580377.pdfIn PDF document text
    • http://atenngo.com/admin/sites/site/documents/39308422287.pdfIn PDF document text
    • http://shahnawazonline.com/uploads/files/bekufawizemakagalobewonu.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606ebf8a25f30---3984711005.pdfIn PDF document text
    • http://qzgj.cn/upload/file/81488136743.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=hukum+perdata+islam+di+indonesia+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_off0000daec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAEC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f2fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2FE 16772 bytes
SHA-256: f69ee0c476a3d119815d849c7ab0a96e46fbed1d4efc41af06e8289b706d6d25
font_02_sfnt_off00011e28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E28 10844 bytes
SHA-256: 17376e5525551a084a1d17fb3e188321d45c10d5cf68aa40705bd158d98a6ef3