Malicious PDF — malware analysis report

Static analysis result for SHA-256 d20435d65513778b…

MALICIOUS

PDF

78.5 KB Created: 2021-09-20 06:11:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: cb0cd18c526c57f55f583e751730b74f SHA-1: 7de7eec50d055d224407664359484c1dd6fae0d4 SHA-256: d20435d65513778b912d7307211ea4d21e8431f6b9ccd1776bfa1d5ccb20e07e
82 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 designed to obscure the true destination. The ML classifier strongly indicated maliciousness, and the presence of a download button lure further supports a malicious intent to trick the user into downloading a payload. The document body is heavily obfuscated and unreadable, preventing a more specific analysis of its content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • 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://history.tlshaa.org.tw/ckfinder/userfiles/files/salowajozi.pdf In PDF document text
    • https://aiwcecckolkata.org/FCKeditor/file/2091461425.pdfIn PDF document text
    • https://unitedfightalliance.jordanadams.com/ckfinder/userfiles/files/5706606160.pdfIn PDF document text
    • http://net-work.cz/data/file/wajalipezawajuduxonanam.pdfIn PDF document text
    • http://cpgny.com/userfiles/files/jiwosases.pdfIn PDF document text
    • http://pensionpoint.cz/userfiles/files/gepodogezagenoz.pdfIn PDF document text
    • http://0975811252cool.linker.tw/files/rorare.pdfIn PDF document text
    • http://studiodugnani.it/userfiles/files/favagajupabidozir.pdfIn PDF document text
    • https://okinawa4d.com/contents/files/62642713153.pdfIn PDF document text
    • http://tainanrup.longi.tw/uploadfiles/files/20210904_224522_8339.pdfIn PDF document text
    • https://alexandrapanayotou.com/web/images/static/file/sinerudaxegenupomazas.pdfIn PDF document text
    • http://kemenyseprosiklos.hu/upload/file/larubegolejalemuna.pdfIn PDF document text
    • http://www.morrisjones.co.uk/EditorImages/file/wipadaxagivibo.pdfIn PDF document text
    • http://citysoupsbellevue.com/uploads/files/64454468758.pdfIn PDF document text
    • https://rwd.webseo.tw/upload/files/noxinugizezabulumuw.pdfIn PDF document text
    • http://aan.kz/ckfinder/userfiles/files/sokewodabuzabok.pdfIn PDF document text
    • http://www.poliklinika-hb.cz/userfiles/file/jakitozexakagolez.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/ef5k6mfa2li2cbid2sb8f9qae6/tawilafetadane.pdfIn PDF document text
    • https://network-italia.com/file/nenipoteditikapaxonexar.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/161383d8a01fc3---weropurakiv.pdfIn PDF document text
    • http://xn--80aiddhbkcq5bcaz.xn--p1ai/upload/files/talitubesujetobimo.pdfIn PDF document text
    • http://songpinhao.com/userfiles/files/rekekazutodefovifevat.pdfIn PDF document text
    • http://www.w.radeton.cz/ckfinder/userfiles/files/gifojoxowadutuguwu.pdfIn PDF document text
    • http://www.creativitaecomunicazione.it/js/lib/ckfinder/userfiles/files/bezalolutotepaji.pdfIn PDF document text
    • https://linardi.ru/files/file/puxokux.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=app+puffin+browser+downloadPDF 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_off0000cd46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD46 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e55d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE55D 10700 bytes
SHA-256: 8e7659915937ee856494588cbbbc85978740fec012fa5ffce442c898970c94f4
font_02_sfnt_off0000fdda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDDA 17960 bytes
SHA-256: bf01172bc83b359938fa902e2436a042acb9d7330291e11ff09176a4235cc8b2