Malicious PDF — malware analysis report

Static analysis result for SHA-256 220b986b67d1b66a…

MALICIOUS

PDF

73.1 KB Created: 2021-09-07 13:54:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: ee30fdc1530e259a9cfb059e9c2425a3 SHA-1: 5306c58516e7d0d9795f07e1f19c1781d9728072 SHA-256: 220b986b67d1b66a792a246a243a456e73ed7394dee90492b6b9dbbf9d3349aa
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to various domains, many of which appear to be compromised or disposable hosting, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for SEO poisoning or phishing. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are sufficient to infer a malicious purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://queure.ru/uplcv?utm_term=grade+10+english+teacher%27s+guide+deped+pdf+unit+1 PDF link annotation
    • http://studio-castiglioni.com/userfiles/files/roxamofama.pdfIn PDF document text
    • http://ylpcl.com/ckfinder/userfiles/files/95350630635.pdfIn PDF document text
    • https://mertlakustika.cz/images/pages/file/2009174040.pdfIn PDF document text
    • http://terezmisszio.eu/files/file/faluwikizevi.pdfIn PDF document text
    • http://whuntex.ru/userfiles/file/55284343435.pdfIn PDF document text
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16086a0aacf7e0---58412921416.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d98116a39ee---89778650331.pdfIn PDF document text
    • https://wroclaw-effatha.pl/grafiki/file/55929731118.pdfIn PDF document text
    • https://wlao.on.ca/wp-content/plugins/super-forms/uploads/php/files/5786fecbe3ef8d10690e338573e98724/bigenaz.pdfIn PDF document text
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608f4d9857ba1---livuxamonelokomuwisuziz.pdfIn PDF document text
    • http://sylvianapoles.com/clients/e/e6/e63d90d46a840f0b3195f531cec11f6e/File/gajudexokivekufokuf.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fccbc7739ea---25416848846.pdfIn PDF document text
    • https://www.rapn.ru/ckfinder/userfiles/files/19531609798.pdfIn PDF document text
    • http://ahxxzx.com/userfiles/202105/file/69954914506.pdfIn PDF document text
    • http://amctop.com/board_data/editor_img/file/202105221027.pdfIn PDF document text
    • http://sochisushi.nl/survey/userfiles/files/taruxotatubojem.pdfIn PDF document text
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608d0ecda4530---lutazuzusivabavuluzo.pdfIn PDF document text
    • https://jollytime.ru/wp-content/plugins/super-forms/uploads/php/files/1c233f34f860eae45cd00bcdb47ff166/zaxomidelu.pdfIn PDF document text
    • http://sjar-tech.com/uploadfile/file///2021080405081758.pdfIn PDF document text
    • https://fultoys.com/userfiles/85034916809.pdfIn PDF document text
    • http://www.southforconstruction.com/frontend/web/ckfinder/userfiles/files/67971609478.pdfIn PDF document text
    • http://www.startservis.sk/novy/ckfinder/userfiles/files/72062000234.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606ee156241fb---51815202836.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16098c29db6431---lazek.pdfIn PDF document text
    • https://mmszke.hu/files/file/14499594976.pdfIn 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://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_off0000b8fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d113.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD113 11124 bytes
SHA-256: eee2b884bb2db9e81efa8f868e124d87bc305d94d934a27b21dea3af5b12525e
font_02_sfnt_off0000ead5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAD5 16804 bytes
SHA-256: 571a961660f4398e39102b7696041f32ff057887420fc8691bf5b18e5da03665