Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8e1291a2db23dea…

MALICIOUS

PDF

72.7 KB Created: 2021-06-14 13:44:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 91c913994d8004f0f0cb1572890b4638 SHA-1: f41e4c6efb17831d3b1eb2cd6f7575d1ba686266 SHA-256: d8e1291a2db23dea02887d11d9506ba0c2df410e33b1bef9dbaf2dc455bb4739
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains numerous external URLs, many of which point to compromised WordPress sites hosting PDF files. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically phishing. The document body, though heavily obfuscated, contains references to 'Prime video not working on windows 10' and 'wkhtmltopdf', suggesting a lure to a fake support or troubleshooting page.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://crysiq.ru/uplcv?utm_term=prime+video+not+working+on+windows+10 PDF link annotation
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160944fe42a8c7---zizulubaperamesimumidat.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/5c95512cdfa09ed816f95339ff8fdaa8/kanowixufivemoz.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/457bf5993bd370145ea3861b1e0fff94/78054528399.pdfIn PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/b12198534a2445e84e58fe4ce2a52827/widojix.pdfIn PDF document text
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607d158d6820a---22731881321.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/160925777c2fb8---85366203905.pdfIn PDF document text
    • https://sinhadventure.com/uploads/file/penomelavumukazenekabuvi.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5ddeb57474---rafupizewitelotubemijure.pdfIn PDF document text
    • http://anhuicrew.com/upload_fck/file/2021-6-14/20210614182222960886.pdfIn PDF document text
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/160bc2d650e40a---fujebofemebov.pdfIn PDF document text
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/9c996885a5016f23f4a7fa96b4e95181/samuj.pdfIn PDF document text
    • http://aps-mes.com/files/file/54882365782.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/hr1ptnmfb7tcchtf345klfnnn0/7020676393.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/160950f5063e69---53981640289.pdfIn PDF document text
    • https://www.digitalsofts.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb11001f790---71337820053.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC40 5316 bytes
SHA-256: ffb0917292ee47db823df95b059f9d9b662bb5ee1c298fa3834dd0ab44467c4d
font_01_sfnt_off0000ee67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE67 10936 bytes
SHA-256: 6b50c4d46593fd1926fe0f2581fd602dfe597cc529a8b9878d47ac9eab8bad2d