Malicious PDF — malware analysis report

Static analysis result for SHA-256 93ce1faf926580c9…

MALICIOUS

PDF

92.8 KB Created: 2021-09-04 06:07:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: d6c534de3cfa81045e62e5925050a79a SHA-1: c2b00b6fdd2b18b59816df4c33fcaad9d3c2dac3 SHA-256: 93ce1faf926580c94cdd160cff2952a719cccb5124763cb176634fc34f63e4de
156 Risk Score

Malware Insights

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

The file was identified as malicious by a machine learning classifier and ClamAV. It functions as a link farm, containing numerous URLs pointing to PDF files hosted on various domains, some of which appear to be compromised. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for these links, suggesting an attempt to obscure the true destination or evade detection. The presence of multiple external URIs and the overall structure point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 http://zentrumok.com/userfile/files/loduji.pdf In PDF document text
    • http://enewind.com/pliki/file/pugixibazovigofubiguriza.pdfIn PDF document text
    • http://energy-labels.com/userfiles/file/54595006742.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/30846850825.pdfIn PDF document text
    • http://eske.hu/wp-content/plugins/formcraft/file-upload/server/content/files/16079d54a22231---jazubiwerosumixe.pdfIn PDF document text
    • https://samsunyapi.com/userfiles/files/tetinepimanupasukeza.pdfIn PDF document text
    • http://host.keraladreamhomes.com/~viswabrahmathach/admin/fckeditor/editor/filemanager/connectors/php/userfiles/file/valilofamedomolojome.pdfIn PDF document text
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/445069f12521b5c8c6f11728fd06ed0f/6561606231.pdfIn PDF document text
    • https://siangyun.com/upfiles/editor/files/33895610990.pdfIn PDF document text
    • https://digireg.ch/upload/40349313667.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1607cabae1f5df---21989036157.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a8d93caeadc---13369697409.pdfIn PDF document text
    • http://dj-venci.com/uploads/pages/files/wesojatoguxuninadorobudaj.pdfIn PDF document text
    • http://nhs-carpediem.com/clients/46367/File/50283198548.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d2ea5c1b8e0---39690921431.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074a3c5c1506---26919021753.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1610d8e7669eb5---32860306559.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/gucmaqa55g1n0s1vfsm41c8823/bibabigotuvufefawofapemut.pdfIn PDF document text
    • http://yaeram.com/userData/board/file/geturi.pdfIn PDF document text
    • http://grafiport.com/userfiles/file/45688859632.pdfIn PDF document text
    • http://vitali-schulz-eiskunstlaufen.de/userfiles/files/fuvex.pdfIn PDF document text
    • http://ciccioinpentola.com/userfiles/files/tixodaneju.pdfIn PDF document text
    • https://rafaela-motores.com/userfiles/file/20260942802.pdfIn PDF document text
    • https://cwlighting.com/wp-content/plugins/super-forms/uploads/php/files/21f68c4c193a62ba325dabdd3fc30387/vigogatujigepezeda.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=grant+proposal+format+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_off0001067a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1067A 18144 bytes
SHA-256: bb9775c9914da3454743de76da56285ed7c22a6b89123ccf612cf8542c4f578d
font_01_sfnt_off000135ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x135AD 10476 bytes
SHA-256: bad9221589fa45c4b63971f016251b5b5de60e47881a285e8e76e952dedd2d74
font_02_sfnt_off00014d79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14D79 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1