Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb5b4ad6dd88a553…

MALICIOUS

PDF

96.3 KB Created: 2021-08-11 14:04:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b1c7ced0b21b1d0cb88ed13b6747d17c SHA-1: 966c77cb3f3815ba3fcbf9e9790fb8b4d7cfcd43 SHA-256: bb5b4ad6dd88a55311b0e883f9f0786407bac9715fd949ab516b04ce9792bb70
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The ML classifier and heuristics indicate this PDF is malicious, likely functioning as a link farm. It contains numerous URLs pointing to potentially compromised CMS upload directories and disposable hosting, suggesting an attempt to distribute or obscure malicious content. The primary attack pattern involves luring users through a malicious attachment to click on these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 5

  • 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://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e400be173b---luvos.pdf In PDF document text
    • http://eurogeographyjournal.eu/admin/fckfiles/file/19049433850.pdfIn PDF document text
    • http://titusrelay.com/clients/e/ef/ef304ccc03541e9e6382bef5f13b0a7d/File/tulutoti.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/c57d2a820d42669943e1c319bdfaa8f3/17091700570.pdfIn PDF document text
    • http://avtrak.ru/ckfinder/userfiles/files/33653321394.pdfIn PDF document text
    • https://ht-cooling-j3t.com/contents//files/81705639367.pdfIn PDF document text
    • http://mariopresto.pl/userfiles/file/fepopewawipapubebopeturu.pdfIn PDF document text
    • https://arrayamed.com/userfiles/file/wolevogudugotavarebolebuf.pdfIn PDF document text
    • https://kurashi-kyoiku.com/cms/dat/upimg/file/xoloxusugov.pdfIn PDF document text
    • http://cetinelektrik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160bc241a2432a---76598443305.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607eebd63ca2f---najodavuzusubufexagusifuf.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b29195db974---13440875922.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/16112eb1835b94---10128660309.pdfIn PDF document text
    • http://asianaccounting.com/admin/fckeditor/userfiles/file/39709110869.pdfIn PDF document text
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160872d86ac736---20287533906.pdfIn PDF document text
    • https://alzubidi.com/userfiles/files/pogulupekukame.pdfIn PDF document text
    • https://bselink.com/userfiles/file/nokemelividofudomokizut.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/8d53ace221b881a1cb0a1ea4dc4cbdb3/zodudedobadozu.pdfIn PDF document text
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/cf8fe14d780d181081fcc464b7943aa6/35426028253.pdfIn PDF document text
    • https://infypos.com/infyposcms/media/mulawevesu.pdfIn PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/16082fcaccae7e---91635537933.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=electric+circuits+11th+edition+cheggPDF 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_off00011318.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11318 18692 bytes
SHA-256: ebc1071a7a7d30451a12c3dcc5e110f0ca41a6fe0466718c4f390dd8095cb634
font_01_sfnt_off00014344.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14344 10620 bytes
SHA-256: b5d18106bda8ed51b168f45f5e073083c918af09ad721c8188c5f1ebbdff8241
font_02_sfnt_off00015b4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15B4C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1