Malicious PDF — malware analysis report

Static analysis result for SHA-256 5140d4c133ce09b2…

MALICIOUS

PDF

81.4 KB Created: 2021-09-14 03:50:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 3bde0daec257be9dd0b1067ff066d7de SHA-1: 6c60199e021685892c61f8a5245106b119db4835 SHA-256: 5140d4c133ce09b265f33b2fc773bb1157dfcdf43fb6d57a5eff563334fc216f
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to disposable hosting and are indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO poisoning by redirecting users to potentially harmful content. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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 http://www.sintsprev-ms.org.br/ckfinder/userfiles/files/2184129476.pdf In PDF document text
    • http://www.findvoters.com/userfiles/file/zimirema.pdfIn PDF document text
    • http://csa.china-led.net/static/editor/ckeditor/ckfinder/upfile/files/73570436305.pdfIn PDF document text
    • http://dietgame.net/admin/fckeditor/data/file/20210903055756.pdfIn PDF document text
    • http://gtlitalia.com/userfiles/files/sovizi.pdfIn PDF document text
    • http://gyndoktors.de/ckfinder/userfiles/files/degogufezetapepov.pdfIn PDF document text
    • http://sochi-vitrazhi.ru/ckfinder/userfiles/files/pogusazowo.pdfIn PDF document text
    • https://masukpt2.com/contents/files/javiziz.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/161356cc095940---wudedewobike.pdfIn PDF document text
    • https://gamepinleri.com/calisma2/files/uploads/sabafoxisuxexapa.pdfIn PDF document text
    • https://palet-school.com/files/files/pixazojewavosunodeweleg.pdfIn PDF document text
    • http://spec-so.ru/sites/default/files/file/fopamapiziwotovax.pdfIn PDF document text
    • http://tcyy88.com/userfiles/file/2021090306095373499.pdfIn PDF document text
    • http://hodoan.net/userfiles/file/50899678860.pdfIn PDF document text
    • http://scarpatti.com/files/xojidosumutezolox.pdfIn PDF document text
    • http://adabaskimerkezi.com/upload/file/48910961602.pdfIn PDF document text
    • https://cafeau1ait.xyz/js/ckfinder/userfiles/files/25270663010.pdfIn PDF document text
    • http://glamour-nsk.ru/ckfinder/userfiles/files/58605724445.pdfIn PDF document text
    • https://doctmcooper.com/userfiles/files/57666691668.pdfIn PDF document text
    • http://madveras.com/ckfinder/userfiles/files/fusakak.pdfIn PDF document text
    • http://vaonhaphatphap.com/images/uploads/files/nuviduboxagel.pdfIn PDF document text
    • http://www.sm.ac.th/ckfinder/userfiles/files/xozetes.pdfIn PDF document text
    • http://hermandadperdon.es/userfiles/file/86518488226.pdfIn PDF document text
    • http://pincesorvarshop.hu/editor_up/fedotukuvigiwomaximobobi.pdfIn PDF document text
    • http://taxilitomerice.cz/ckfinder/userfiles/files/titoratekebowu.pdfIn PDF document text
    • http://analhospital.net/file/files/4907471255.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=comparative+superlative+exercises+worksheetPDF 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_off0000d647.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD647 11012 bytes
SHA-256: 29cc5ee809b11d1de4dc3dbfa98d1f896bf4aba3f88adcc8ed1c867d1cb982c5
font_01_sfnt_off0000f002.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF002 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010814.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10814 18804 bytes
SHA-256: dedf20134d4e373f0c6f22a42edb12b0f6cf0ee1223d311d656aad748e4eb8fe