Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8db261aadb8b596…

MALICIOUS

PDF

72.0 KB Created: 2021-06-08 20:03:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 8088a597348269a8a1b8bddd11378c6f SHA-1: e5411e7c6acf6e4bcbf0b6ec8d8d6e87740738a1 SHA-256: c8db261aadb8b596fc844e6105335b9786a2e424e146e41ba784b54c41ea0c8d
156 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://nomylo.ru/uplcv?utm_term=pdf+compressor+to+less+than+100kb PDF link annotation
    • http://residencecarlofelice.com/userfiles/files/woserulegatore.pdfIn PDF document text
    • https://gfow.om/wp-content/plugins/super-forms/uploads/php/files/susaul8dutqa3m1166fb6idmf0/77126684722.pdfIn PDF document text
    • https://fastcomputer.vn/wp-content/plugins/super-forms/uploads/php/files/579e07460c89daf6ce11f25517fd7e32/gikilexes.pdfIn PDF document text
    • http://agendatourvietnam.com/hinhanh/file/23630297728.pdfIn PDF document text
    • http://www.pianoszimmermann.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609f2473ee4c6---gamujimuwegedopoka.pdfIn PDF document text
    • https://refour.dk/wp-content/plugins/super-forms/uploads/php/files/62b50125595aaa69d33b4cc0c35b8aab/91089311526.pdfIn PDF document text
    • http://atol-res.pl/uploads/file/dezanokanupuzawiluzu.pdfIn PDF document text
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc5eea8e05f---80338208029.pdfIn PDF document text
    • https://grafitpoint.ru/wp-content/plugins/super-forms/uploads/php/files/4ba6cf9e665286caf1afb94325efe773/75095684620.pdfIn PDF document text
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/380c2cf52c24e1f4366a2b0a9dfa9993/87381266835.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8af57c8e25---65923363254.pdfIn PDF document text
    • http://bakoca.hu/files/file/boduluj.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/16070c8bf7bce4---82429119145.pdfIn PDF document text
    • https://1877painters.com/FCKeditor/file/52725470249.pdfIn PDF document text
    • http://assistance.uz/images/shared/file/miwafovotanerilexugekoza.pdfIn PDF document text
    • http://dok-vo.ru/userfiles/file/kadigalididogime.pdfIn PDF document text
    • http://payassistinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099d0509ec96---pigifawifozumegixegezekux.pdfIn PDF document text
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160775b3632f44---19330064351.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_off0000dd68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD68 5796 bytes
SHA-256: 7045ccef902fc69c8c845352f3cc3f3950de5e2cd6f2f804d060ed48ae3e652d
font_01_sfnt_off0000f0f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0F0 10256 bytes
SHA-256: 431eeeb2f3176e885586ea8188fefad7649bafcd56c35f78b2f6fd5d5908164e