Malicious PDF — malware analysis report

Static analysis result for SHA-256 858b8e33b3131676…

MALICIOUS

PDF

76.9 KB Created: 2021-09-21 11:23:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: b6d86c8b046c69a868304df1f9eb7274 SHA-1: fa03a513fa3465ba904852e7cd4a0fa17e53e1ac SHA-256: 858b8e33b3131676e7dacb8e8672ebf65f8929c6f7de13ed9662a5a570a312af
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF was flagged by a machine learning classifier and ClamAV as malicious, exhibiting characteristics of a phishing and trojan delivery mechanism. The 'SE_BROWSER_INSTALL_LURE' heuristic indicates the document likely prompts the user to install a fake browser update or extension. While no scripts were directly extracted, the presence of numerous links to compromised CMS upload storage and disposable hosting suggests a multi-stage attack where the PDF acts as a lure to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://neuchina.org/userfiles/file/maxidamifonolalazuguzubox.pdf In PDF document text
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/161477ee723b8d---63141421542.pdfIn PDF document text
    • http://dulichtantai.com/files/uploaded/files/13933672651.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1612ec89f98759---rubixapot.pdfIn PDF document text
    • https://nailseasupportgroup.com/wp-content/plugins/super-forms/uploads/php/files/0a650380107a0d3d614a2ebdb98533b7/fubuzafemiropakode.pdfIn PDF document text
    • http://machinesupplier.cn/data/product/file/2021918_172735_560.pdfIn PDF document text
    • http://studiolorenzino.eu/userfiles/files/luvomer.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/161407adf12236---pugumuvawepe.pdfIn PDF document text
    • https://tattica.byespresso.com/app/webroot/files/upload/files/3255956737.pdfIn PDF document text
    • http://odnoklassniki-files.ru/images/uploads/files/zeforod.pdfIn PDF document text
    • http://nessium.net/userfiles/file/taxijoxepu.pdfIn PDF document text
    • http://noospc.ru/SITE/files/editor/file/88197108431.pdfIn PDF document text
    • https://glycocalyx.nl/userfiles/image/file/62253784083.pdfIn PDF document text
    • http://aeusjtu.pretty-match.com/upload/files/ganev.pdfIn PDF document text
    • http://forma8.kz/ckfinder/userfiles/files/87614375645.pdfIn PDF document text
    • http://beccaro.it/userfiles/files/pisewivusoluzuperuso.pdfIn PDF document text
    • http://werder-ritter.de/UserFiles/File/diremarasalafodasebeko.pdfIn PDF document text
    • https://agrando.cz/files/file/37422244629.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140059866db7---78318074251.pdfIn PDF document text
    • http://banlinhkienlaptop.com/userfiles/file/24709473645.pdfIn PDF document text
    • http://karmakonnect.org/DrumiBhatt/karmakonnect.org/Final/ckeditorimage/files/53043448066.pdfIn PDF document text
    • http://scard.vn/app/webroot/uploads/files/95311292627.pdfIn PDF document text
    • http://safetruck.gr/images/file/22503816582.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/013612ea2c136a6bb8210491eda895da/vumigularak.pdfIn PDF document text
    • http://bhttourist.com/upload/fckimagesfile/teremadozipor.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=free+websites+to+watch+friendsPDF 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_off0000c93b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC93B 16816 bytes
SHA-256: 2a37655bcca2ae5b350b538d110d4fe46565d86f984430bbb11f43a6dfa58277
font_01_sfnt_off0000f4e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010cf8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CF8 10728 bytes
SHA-256: a0f24fc37e9876451c11b29b20dc56725a43b627b08d78e3a61a47969cb9a201

Open this report in the interactive analyzer, or submit your own file for analysis.