Malicious PDF — malware analysis report

Static analysis result for SHA-256 c50a162a9ec6ddc4…

MALICIOUS

PDF

72.1 KB Created: 2021-09-25 20:02:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 65b594e5a3836f9fe43aaaf75dd3403e SHA-1: 6de1b936b94b133098325e1138f046130f60a237 SHA-256: c50a162a9ec6ddc4cc25648303e356b1ca56f11d66f0d841c8cc1bd9e2890d9d
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by multiple heuristics, including ML and ClamAV, as malicious. It contains embedded JavaScript and numerous external URIs, many of which point to link farms on potentially disposable hosting. The embedded JavaScript likely facilitates the redirection to malicious sites, contributing to a phishing or malware distribution attack. The presence of embedded JavaScript suggests an attempt to execute code within the user's browser or PDF reader.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://rescue119.org/userfiles/file/damasidejojefa.pdf In PDF document text
    • http://cuacuonnhaxuongbinhduong.com/upload/files/84085066920.pdfIn PDF document text
    • http://myshopgroup.com/userfiles/files/sovixalalebuk.pdfIn PDF document text
    • https://skillmapmagazine.com/ckfinder/userfiles/files/96961901105.pdfIn PDF document text
    • https://mcdelandes.ca/uploads/file/wilukadazeni.pdfIn PDF document text
    • http://nowator-zpu.pl/userfiles/file/kenekiwipu.pdfIn PDF document text
    • http://thegrcinstitute.org/app/webroot/js/ckfinder/userfiles/files/28253644444.pdfIn PDF document text
    • http://buyo-g.net/userfiles/file/benuxotefese.pdfIn PDF document text
    • https://abandassociates.com/ckfinder/userfiles/files/64610622709.pdfIn PDF document text
    • http://optikametuje.cz/userfiles/file/96633559871.pdfIn PDF document text
    • http://khacvietlaser.vn/public/images_news/files/20209331734.pdfIn PDF document text
    • https://premiersuli.hu/files/files/51714026408.pdfIn PDF document text
    • https://ms01bet.com/contents/files/gufuw.pdfIn PDF document text
    • http://buffagiuseppeinfissi.com/userfiles/files/54192474275.pdfIn PDF document text
    • https://cafesca.info/ckfinder/userfiles/files/jorenupadagagevex.pdfIn PDF document text
    • http://www.jasolasia.com/image/upload/File/12162111416.pdfIn PDF document text
    • http://fnathservices.com/upload/file/6010933974.pdfIn PDF document text
    • https://www.bbmnetlicitacoes.com.br/cms/ckfinder/upload/files/60901484374.pdfIn PDF document text
    • https://shevian.com/images/file/mererobukenotux.pdfIn PDF document text
    • http://silverspringabw.com/uploads/files/wigojixeziruk.pdfIn PDF document text
    • http://xn--9n2bn9mz3aba29g44r4o0a.kr/fckeditor/userfiles/image/68984259537.pdfIn PDF document text
    • http://go-pxl.com/uploads/files/vusekinabavonituso.pdfIn PDF document text
    • https://digitaldaya.com/imagenes/file/xirazidifusurogoza.pdfIn PDF document text
    • https://almudenafernandez.co/ckfinder/userfiles/Files/42237666249.pdfIn PDF document text
    • http://pferdplus.at/sites/pferdplus.at/files/file/55595370911.pdfIn PDF document text
    • https://deconkhoemanh.com/wp-content/plugins/super-forms/uploads/php/files/07f1smq57shuoua0fb4q3d3310/tegisozijunez.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=xiaomi+wear+app+androidPDF 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_off0000b482.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB482 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC99 10332 bytes
SHA-256: 1d09500b6e9a43fe8c6e5a505c03abdb3f26e0dfe9a1161435f689cba95e1ad5
font_02_sfnt_off0000e3d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3D7 17776 bytes
SHA-256: b557f62699ec2f4ae7dab5c85d27634f36a43c5e096c74a2bfe3c55a4aea5507