Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4f57b920b7b686e…

MALICIOUS

PDF

80.7 KB Created: 2021-09-16 20:35:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 47d7d65b6e996c7cbd1ae0ca1803b3d7 SHA-1: 45bc09ddd43ffd7b92d910f2f1fef93a2a113abc SHA-256: c4f57b920b7b686e57a615070cc4d819be7d33d0f2f9bdc17527331b6683566c
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are part of a link farm hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to trick users into visiting these links for malicious downloads or phishing. The presence of JavaScript suggests an attempt to execute code within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://pistant.ru/uplcv?utm_term=avatar+movie+in+telugu+free+download+utorrent PDF link annotation
    • https://hygradeinsulators.com/images/uploads/file/44560206334.pdfIn PDF document text
    • https://aartipalette.com/userfiles/file/xatituxejijavo.pdfIn PDF document text
    • http://karcannakliyat.com/userfiles/file/virazeriral.pdfIn PDF document text
    • https://fptica.ru/images/file/riwanizuwowukogipi.pdfIn PDF document text
    • https://linlinline.biz/js/ckfinder/userfiles/files/21566848065.pdfIn PDF document text
    • https://szekszardportal.hu/userfiles/file/85998376807.pdfIn PDF document text
    • http://wojno-stal.pl/pliki/file/86113182536.pdfIn PDF document text
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613f6368ca185---xofituwuzejabukeziranu.pdfIn PDF document text
    • https://inoxquochoang.com/app/webroot/files/images/pages/files/nakikegibunusijaje.pdfIn PDF document text
    • http://mellorymotors.ru/admin/ckfinder/userfiles/files/somarotudavexigez.pdfIn PDF document text
    • http://www.valathors.com/ckfinder/userfiles/files/19823224265.pdfIn PDF document text
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/16133f04b30b71---69469629704.pdfIn PDF document text
    • http://maynenkhiinverter.com/media/ftp/file/doleleba.pdfIn PDF document text
    • https://pointvirgule.ca/upload/editor/file/kufemag.pdfIn PDF document text
    • http://xinyaoqiye.com/upload_fck/file/2021-9-12/20210912190542637552.pdfIn PDF document text
    • https://shreenatharcade.com/userfiles/file/somaladajivofegubofo.pdfIn PDF document text
    • http://mai-colle.jp/userfiles/file/37623780971.pdfIn PDF document text
    • https://4of100churchstreet.com/assets/media/files/26235030073.pdfIn PDF document text
    • http://artin-intranet.com/ckupload/files/biwuwosuv.pdfIn PDF document text
    • http://springgalleryng.com/Images_upload/files/86510945545.pdfIn PDF document text
    • https://widepolymers.com/userfiles/file/42090870383.pdfIn PDF document text
    • https://sibiucuratenie.ro/fckeditor/userfiles/file/dogodebetagifex.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16130d0502e481---degiziwij.pdfIn PDF document text
    • https://oykufestivali.com/ckfinder/userfiles/files/2073352452.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_off0000d76e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD76E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF80 17156 bytes
SHA-256: 446a845bbd9293ed64accf7dfafe904f1000594fa321374d3e98c7500a231fe1
font_02_sfnt_off00011c08.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C08 10764 bytes
SHA-256: a6961445eab53d7f45ff54081a3ba829f27d7254f40ca60d8e62ea1ab263ad93