Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d51a6e68f9c977a…

MALICIOUS

PDF

82.6 KB Created: 2021-09-18 12:57:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 6fdaf07c2188eb720df3ae7996c90b97 SHA-1: 64364fa5125dec34565c91bb0e8e9a9260d9dc53 SHA-256: 4d51a6e68f9c977a48b71f516a8e95ea4ceff715c622c20afb816ab3216f1b73
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to domains associated with compromised CMS uploads or disposable hosting, indicating a link farm. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the heuristic firings suggest the primary purpose is to redirect users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://myredm.ru/uploads/file/felozaga.pdf In PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613a5a2b72c47---93503490286.pdfIn PDF document text
    • https://jimsdelibrookhaven.com/demo/jimsdeli/admin/userfilesfile/zologewela.pdfIn PDF document text
    • https://pindimana.in/uploads/file/28588850558.pdfIn PDF document text
    • https://muzpony.de/obrazki/file/movela.pdfIn PDF document text
    • https://memo-log.com/userfiles/file/vudaluvi.pdfIn PDF document text
    • http://ajisushionline.com/uploads/files/babaxodovudisajuripejew.pdfIn PDF document text
    • http://sjar-tech.com/uploadfile/file///2021091118082341.pdfIn PDF document text
    • http://teusz.pl/UserFiles/file/57764530290.pdfIn PDF document text
    • https://kga-am-adlergestell-ev.de/kga/ckfinder/userfiles/files/58552849375.pdfIn PDF document text
    • http://tyros-club.de/userfiles/file/7090759377.pdfIn PDF document text
    • https://www.uflo.edu.ar/ckfinder/archivos/documentos/rojiwonol.pdfIn PDF document text
    • http://aallergy.netlovestories.com/upload/files/futiw.pdfIn PDF document text
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613b91695f50f---60575583051.pdfIn PDF document text
    • https://verlauf-ekb.ru/admin/ckfinder/userfiles/files/patukirofomofozegelumiro.pdfIn PDF document text
    • http://www.fdconsult.qa/public/uploads/cms_files/nenaseraxaxegofif.pdfIn PDF document text
    • http://qdxqw.com/uploadfile/file/negetibunawowizeda.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/b1588d030d26c3d3ec1e9f0644c90604/11452319650.pdfIn PDF document text
    • http://aylabawadi.ae/userfiles/file/rabinupobi.pdfIn PDF document text
    • https://ribaczpeter.hu/files/file/wuliwobake.pdfIn PDF document text
    • https://honghow.com/ckfinder/userfiles/files/divuwatazapojonavo.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/1613d0c806548b---kufalo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=games+bottle+flipPDF 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_off0000dc13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC13 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f42a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF42A 10496 bytes
SHA-256: 39890e2f299049748a11f88167e2ab2ca912996dcb13fea858dfead2ab077cd9
font_02_sfnt_off00010bdb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BDB 18884 bytes
SHA-256: 6f5c764aed1a9de72b56379785811089e71c732005c96017019f8c365d08e16a