Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef51b901ceda3d51…

MALICIOUS

PDF

98.9 KB Created: 2021-09-16 16:31:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 05dc03374b75f99733aa4f4fb8eaebdd SHA-1: 61d3fcf69b40d9fe27ceb790c2d05e1ef8cf701a SHA-256: ef51b901ceda3d51290f9c415a43d2a79cf12adafbe6e73f21c5218f2e57bcca
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external URIs, many of which are part of a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing sites or download further malware. The embedded JavaScript is a common technique for exploiting PDF vulnerabilities or initiating malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9785

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
  • 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://infrive.ru/uplcv?utm_term=gb+music+player+apk PDF link annotation
    • http://instalater-macecek.cz/klienti/devel/sneznerolby.cz/ckfinder/userfiles/files/61769151837.pdfIn PDF document text
    • http://rotarybrescello.it/userfiles/files/wivamutugavekupebokof.pdfIn PDF document text
    • https://gs-hemeringen.de/ablage/userfiles/files/baramizewekujuvobixamivos.pdfIn PDF document text
    • http://vladjurnalist.ru/archive/file/gipasuluvesara.pdfIn PDF document text
    • http://utpcomp.ru/uploads/files/99563061053.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/16139fc938f94a---52167386807.pdfIn PDF document text
    • http://dxczx.com/ckfinder/userfiles/files/20210916_060852.pdfIn PDF document text
    • http://mertcelikkapi.com/userfiles/file/22203554360.pdfIn PDF document text
    • https://0924055971.com/uploads/files/202109151533534865.pdfIn PDF document text
    • https://onlineadda.net/ckfinder/userfiles/files/vifujuwale.pdfIn PDF document text
    • http://zhfangyuan.com/uploadfiles/files/48535815402.pdfIn PDF document text
    • http://billedbutikken.dk/articlefiles/file/6872652696.pdfIn PDF document text
    • http://daieimotors.com/js/upload/files/55551039539.pdfIn PDF document text
    • http://php-lounge.de/userfiles/file/vomatofetululukutimaxor.pdfIn PDF document text
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131730917820---1621253003.pdfIn PDF document text
    • http://nitexprofi.cz/userfiles/file/lekogosuxupotilonojuwad.pdfIn PDF document text
    • http://perilatomsk.ru/ckfinder/userfiles/files/63325051937.pdfIn PDF document text
    • https://uetty.xyz/js/ckfinder/userfiles/files/18911857339.pdfIn PDF document text
    • http://arqing.es/ckfinder/userfiles/files/jagejowoviwuwabomexefa.pdfIn PDF document text
    • http://trieuduong.com/images/Download/74858833444.pdfIn PDF document text
    • http://xn--42-jlclgg6a3e.xn--p1ai/userfiles/file/tamozag.pdfIn PDF document text
    • http://investin-khj.ir/ckfinder/userfiles/files/42278378441.pdfIn PDF document text
    • http://izeninfo.net/admin/upload/files/54150821167.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613b929425ed2---26651212326.pdfIn PDF document text
    • http://bulgankhangai.mn/userfiles/files/vewafu.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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ede3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDE3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000105f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105F5 25556 bytes
SHA-256: 4ed770f60c6025cdca4f4b572fb25b3fc59cfd2c6223f7269852d41483fd5613
font_02_sfnt_off0001451a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1451A 1680 bytes
SHA-256: 6c08887b596ecb472c5a0482df8c2f828d83fc5b5d16111ed0caa1fced1b35dc
font_03_sfnt_off00014d11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14D11 16712 bytes
SHA-256: 58caf4dfb72c2d511e156b6980b746f1bc0bb7b5bd64e7b2568e2feacc951986
font_04_sfnt_off000164f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x164F3 10700 bytes
SHA-256: dc0c1dab4a2f37b567238d380800323c93ff4dea60d41bfee86c1f5e23d6f2a6