Malicious PDF — malware analysis report

Static analysis result for SHA-256 8723c583432bdcf4…

MALICIOUS

PDF

87.7 KB Created: 2021-09-18 20:22:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: bb8477a97c96da87d8d7ad6e82c4819a SHA-1: 3bb2a0a7c4704b1f54b7f4da6f43bd348f2b05a4 SHA-256: 8723c583432bdcf4939281dc25ddf262fcb8e77ad9735b091408ca9a17898b66
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to external domains, suggesting it functions as a link farm or phishing lure. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this, indicating the PDF is structured to redirect users to a large number of potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 5

  • 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.
  • 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://coretry.ru/uplcv?utm_term=emu+ps3+android PDF link annotation
    • http://historico.uts.edu.co/portal/app/ckfinder/userfiles/files/bimoleziji.pdfIn PDF document text
    • http://tmkb.org.tr/ckfinder/userfiles/files/mosaneperixemedopuf.pdfIn PDF document text
    • http://mygotour.com/FileData/ckfinder/files/20210910_0A0805432304D8C2.pdfIn PDF document text
    • https://asoriofrio.org/ckfinder/userfiles/files/27757930073.pdfIn PDF document text
    • http://visusmarble.com/images_upload/files/29606585136.pdfIn PDF document text
    • https://everestart.com/images/stories/file/zegof.pdfIn PDF document text
    • https://theelementrama9.com/userfiles/files/12226396735.pdfIn PDF document text
    • http://teamhead.net/userfiles/file/moridis.pdfIn PDF document text
    • http://pawsandtiaras.com/ckfinder/userfiles/files/ribufatajafopipijadebuwe.pdfIn PDF document text
    • https://christembassybarking.org/wp-content/plugins/super-forms/uploads/php/files/8e9a1cfd98490bef227502e796773d35/podunikivomafivorovosakut.pdfIn PDF document text
    • https://www.cdsale.org.au/application/third_party/ckfinder/userfiles/files/73163835831.pdfIn PDF document text
    • http://aristosaigonhotel.vn/uploads/files/20027003386.pdfIn PDF document text
    • http://cecev.com/stockages/files/76465041221.pdfIn PDF document text
    • https://saglamahsapkutu.com/img/editor/image/file/96011173846.pdfIn PDF document text
    • https://bibonatura.hu/ckfinder/userfiles/files/mefigalaz.pdfIn PDF document text
    • http://www.ih-consultant.com/ckfinder/userfiles/files/sanafelitoxomiwekakugegej.pdfIn PDF document text
    • http://stroi-sistema.ru/img/xupotosat.pdfIn PDF document text
    • https://www.solucionaesp.com/ckfinder/userfiles/files/61823804648.pdfIn PDF document text
    • http://niszczeniewaw.pl/userfiles/file/94154704298.pdfIn PDF document text
    • http://slovbau.sk/test/userfiles/file/fixuzuxoluturu.pdfIn PDF document text
    • http://duszek-lasu.pl/userfiles/file/xukibapofekizetivikorot.pdfIn PDF document text
    • https://vrindaindia.com/php/joseph/uploads/file/zarijunubi.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1614559e37ca5e---namogepazodomevarowewumi.pdfIn PDF document text
    • http://pactolous.hu/upload/file/81537171616.pdfIn PDF document text
    • https://theloneranger.tv/clients/loneranger/ckfinder/userfiles/files/zonufedop.pdfIn PDF document text
    • http://radio-salsa.com/php/rs/filesupload/file/68337256661.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_off0000efff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFFF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010816.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10816 10532 bytes
SHA-256: 5b4b6d6ab3fbf4dc42365e849ee7db53f0f8f27289d28d89e053172ca939f3d1
font_02_sfnt_off00011fef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FEF 18852 bytes
SHA-256: 6c61695315d9203cd2719dd1082ac84ea6d50e6891e95ca44ebe96d7c34b2e52