Malicious PDF — malware analysis report

Static analysis result for SHA-256 77bfe2779adc05ec…

MALICIOUS

PDF

76.2 KB Created: 2021-06-14 13:19:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 4aa52ee6b391eb00cd4bc60c467438a7 SHA-1: 3f10b327fec2acf3abed5102e5821fd31552ea7e SHA-256: 77bfe2779adc05eca3e21e7e7eb688749c96fb3cbe9e984b56693602f4442b3f
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file contains a large number of external URIs, many of which point to compromised WordPress installations. The ML classifier strongly indicates maliciousness. The document appears to be a link farm designed to direct users to potentially malicious or SEO-manipulated content hosted on various domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://cructi.ru/uplcv?utm_term=nslookup+package+in+rhel+7 PDF link annotation
    • https://diversified-nj.com/wp-content/plugins/super-forms/uploads/php/files/58d6ebbbe279f1c60e942b32b0dda431/dubod.pdfIn PDF document text
    • https://outsourcedbackoffice.co.uk/wp-content/plugins/super-forms/uploads/php/files/de275df6009e8032403a04bd32904151/zesup.pdfIn PDF document text
    • http://jointrilogy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a79064f1fa2---wewerijiwatafi.pdfIn PDF document text
    • http://allg-gyn.ch/userfiles/file/74080136960.pdfIn PDF document text
    • http://riskhedgetech.com/uploaded/file/2046771386099114ac61f5.pdfIn PDF document text
    • http://veterinariomauracotti.it/userfiles/files/20279649137.pdfIn PDF document text
    • http://www.bufolari.com/public/immagini/file/18687173582.pdfIn PDF document text
    • http://vilaportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608632bd41566---gotisoxuzojepe.pdfIn PDF document text
    • http://asea-admin.com/_userfiles/file/20210504132834.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/gut39adb8hfj2htp52bgfo8ash/20695645933.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/t114jov3cufos3apmq7697u6b0/rigofaja.pdfIn PDF document text
    • https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608f57f6e10d7---21721863345.pdfIn PDF document text
    • http://kardelendalgicpompa.com/uploadfiles/file/99069511534.pdfIn PDF document text
    • http://sns.hu/_user/file/vivifimexezefasevemefeb.pdfIn PDF document text
    • http://fincasotilloviejo.es/files/sotillo/_repo/file/19182820538.pdfIn PDF document text
    • http://ankurgroups.com/userfiles/file/25440429607.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e0f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0F8 5308 bytes
SHA-256: 8c8b400adca9c180278da2e152224fb3b1143a0db4423f0e2588bc8b08d01cf7
font_01_sfnt_off0000f304.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF304 1800 bytes
SHA-256: daad3f347a4f42f432ee9983e619a7c063e36761dba5934b469418034847e28e
font_02_sfnt_off0000fb92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB92 12020 bytes
SHA-256: 5255b17f2bda2644db530653822205605f01ef47cd1078015c6ea0665105c694