Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4a3f636d3c28236…

MALICIOUS

PDF

69.3 KB Created: 2021-10-03 05:12:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: bbe9620a950a72190fe2bfa2935ad108 SHA-1: 600e27691936902adb126bacaefd4ace02ecb7ba SHA-256: a4a3f636d3c28236560ca40b912252446dc9bfff2dd98828a0a3233a7736c5a5
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs, with one heuristic specifically identifying it as a link farm on disposable hosting. While no scripts were extracted, the presence of external URIs and the overall structure suggest an attempt to redirect users to potentially harmful content or for SEO poisoning.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 http://encino.kopanramen.com/uploads/files/wagojanime.pdf In PDF document text
    • https://abrasco.org.br/ckfinder/userfiles/files/digotag.pdfIn PDF document text
    • http://svaz-podnikani.cz/files/file/sojilexaxumatudakagebagaj.pdfIn PDF document text
    • https://x-software.cz/data/file/wutaroretagetegoxod.pdfIn PDF document text
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/16153a4d9742bb---bawopuwikomikumenapes.pdfIn PDF document text
    • http://denki-shonan.com/uploadsfile/vebevexiwix.pdfIn PDF document text
    • http://king-ber.com/UploadFiles/file/20210914001225281.pdfIn PDF document text
    • http://immodraft.nrw/images/architekten_agentur_images_/file/9884608469.pdfIn PDF document text
    • http://manchetenewsms.com.br/ckfinder/userfiles/files/bixaf.pdfIn PDF document text
    • http://globalnetworks.de/www.galabau-poscher.de/main/preview/ckfinder/userfiles/files/91557251781.pdfIn PDF document text
    • http://robfredo.com/userfiles/file/81741157055.pdfIn PDF document text
    • http://fotografoenricogiampieri.it/userfiles/files/lifetutereza.pdfIn PDF document text
    • https://cosmopolitanhotel.lastrada.bg/uploads/wysiwyg/files/98247506326.pdfIn PDF document text
    • https://alicantea.centralcms.cloud/galeria/files/sorobapejesusovap.pdfIn PDF document text
    • http://cathugo-catamarans.de/res/wysiwyg/file/48399337097.pdfIn PDF document text
    • http://m-s-g.ru/userfiles/files/5794650159.pdfIn PDF document text
    • http://esistore.lu/userfiles/file/dubisomijaf.pdfIn PDF document text
    • https://tskrea.com/userfiles/file/gemosovifasu.pdfIn PDF document text
    • http://chinalanpa.com/images/upload/File/raputejev.pdfIn PDF document text
    • http://jumpstart.mobi/ckfinder/userfiles/files/lixazad.pdfIn PDF document text
    • http://longchimvac.net/app/webroot/uploads/files/temibefovatimanimuj.pdfIn PDF document text
    • http://techbico.vn/uploads/image/files/visawa.pdfIn PDF document text
    • https://jackinthegym.com/uploads/files/202109162134057974.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=was+were+exercises+for+beginners+pdfPDF 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_off0000b035.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB035 15100 bytes
SHA-256: 81f0e1794f9e92586a99b8a86b37c35aeda28d8ed0b653ad3a465b4eb2ba95f5
font_01_sfnt_off0000d648.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD648 10972 bytes
SHA-256: 51decb5b7e1f0f8b2e08232633bf5a7e9082fa646a7797494ea1e9ab1c662b87
font_02_sfnt_off0000ef89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF89 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1