Malicious PDF — malware analysis report

Static analysis result for SHA-256 92caa76db97f4ac5…

MALICIOUS

PDF

84.1 KB Created: 2021-09-11 06:13:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: b11b6ca7477079711be8727f5fd19e65 SHA-1: a76a431e7b4ece3dec738d78583edc534b979ca7 SHA-256: 92caa76db97f4ac596051406fb39303c95fcefe3e2c5ffb857e23121f005a65c
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains embedded JavaScript and numerous external URIs, many of which point to PDF files hosted on potentially disposable domains, indicating a link farm designed to host malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to trick users into downloading further malware. The presence of embedded JavaScript suggests it may be used to facilitate the download or execution of a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://yaofangpeixun.com/upload/files/72563936492.pdf In PDF document text
    • https://ventsistem-bg.com/userfiles/file/jonixosufiwi.pdfIn PDF document text
    • http://centonze-vini.com/userfiles/files/46059676362.pdfIn PDF document text
    • http://tverzhilservis.ru/foktver.ru/ckfinder/userfiles/files/70996457394.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613851c387eb2---53375974459.pdfIn PDF document text
    • http://trineckevzdelavani.cz/webpagebuilder/ckfinder/userfiles/files/jidibafuxosejiwanakufar.pdfIn PDF document text
    • http://carrasvilla.es/uploads/files/piguzajapisovarixarirusiw.pdfIn PDF document text
    • http://www.siposferenc.hu/html/98175935579.pdfIn PDF document text
    • https://pfhotel.gr/ckfinder/userfiles/files/55785687133.pdfIn PDF document text
    • https://at-studio.tw/app/webroot/userfiles/files/20210906_161600.pdfIn PDF document text
    • https://hsiaoying.com/userfiles/file/27362143230.pdfIn PDF document text
    • https://pensiunea-escape.ro/ckfinder/userfiles/files/goxegotefufovul.pdfIn PDF document text
    • https://pasarangroup2.com/contents/files/49057196277.pdfIn PDF document text
    • http://winecellarkeeper.com/ckfinder/userfiles/files/tutovelumefusugosekiki.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613be46113b8f---27930885350.pdfIn PDF document text
    • http://www.koeru.eu/failid/file/34633566425.pdfIn PDF document text
    • http://veewood.com/file_media/file_image/file/nivamobevezix.pdfIn PDF document text
    • http://changrung.com/ckfinder/userfiles/files/80439145382.pdfIn PDF document text
    • https://cosmopolitanhotel.eu/uploads/wysiwyg/files/49566613822.pdfIn PDF document text
    • https://fonixkoncert.hu/upload/file/99702696981.pdfIn PDF document text
    • http://aircond.md/upload_fck/file/zegenila.pdfIn PDF document text
    • https://bcbc3399.com/upload/files/44257243794.pdfIn PDF document text
    • http://studiomalpocher.it/userfiles/files/60043785162.pdfIn PDF document text
    • https://sensormaticltd.com/app/templates/js/ckfinder/userfiles/files/16945868174.pdfIn PDF document text
    • http://topenglish.sk/app/webroot/gallery/files/mumofojiguto.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=golf+clash+coin+generatorPDF 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_off0000e200.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE200 10656 bytes
SHA-256: 2022f9b71f20e954d5799734fc5bb3667716ee0d3c1c8fab4eaa1265834dceee
font_01_sfnt_off0000fa64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA64 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011276.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11276 18796 bytes
SHA-256: d55165d2e23c2480df5ce321cf99503cfa94fcdf916a8a0fe45182a23bbed63b