Malicious PDF — malware analysis report

Static analysis result for SHA-256 918d220e5663f745…

MALICIOUS

PDF

73.0 KB Created: 2021-09-28 15:14:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: a91001638cd95ff34cfcf934408f1536 SHA-1: 1a49ee84744db5acc5904211d1ebcb751463ed14 SHA-256: 918d220e5663f745df348ae6adf6a14680e259426961d1d413513a4d1833c0b6
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and a link farm pointing to compromised WordPress uploads and disposable hosting. The embedded JavaScript likely facilitates the redirection to malicious URLs, such as the one found in the PDF_URI heuristic, which is part of a larger link farm strategy. This suggests the document is designed to lead users to external sites for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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
  • 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.
  • 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 https://pixomot.ru/uplcv?utm_term=android+client+server PDF link annotation
    • http://stavclearing.ru/upload/files/55581332105.pdfIn PDF document text
    • http://giovanninociti.com/userfiles/files/3947097417.pdfIn PDF document text
    • http://uptindia.com/newsimages/file///70217819682.pdfIn PDF document text
    • http://asupuro.com/upload/save_image/files/47876208211.pdfIn PDF document text
    • http://vizcsap.hu/files/file/xiwiva.pdfIn PDF document text
    • http://liweisteel.co.th/ckfinder/userfiles/files/96211990764.pdfIn PDF document text
    • http://pasted-radio.de/web/files/19626727678.pdfIn PDF document text
    • https://ozora.schaffsen.com/contents/file/denezuridedasimeba.pdfIn PDF document text
    • http://cybernet.asia/UserFiles/File/8682569820.pdfIn PDF document text
    • http://connect-event.fr/ckfinder/userfiles/files/94169521963.pdfIn PDF document text
    • http://www.ishvani.com/www/js/ckfinder/userfiles/files/85823832136.pdfIn PDF document text
    • http://lab4050.com/upload/editor/file/14825207237.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146474a78fc3---88636646979.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/161373c1b297a6---folapekoxup.pdfIn PDF document text
    • http://innobiztour.com/FileData/ckfinder/files/20210905_0E8C9AD66C4C5C67.pdfIn PDF document text
    • http://tauroconsulting.pl/userfiles/file/kizonewiwisojilisadivefu.pdfIn PDF document text
    • http://hyundaiokla.com/uploads/files/76102322762.pdfIn PDF document text
    • http://corporatiegids.nl/uploads/files/megaxijaruleparav.pdfIn PDF document text
    • https://rmp-familienanzeigen.de/cms/files/fizokozetudisosazafa.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/3776738228.pdfIn PDF document text
    • http://iknow.pl/files/file/66885651740.pdfIn PDF document text
    • http://triatlonbizuterie.cz/sites/default/files/file/pexumivizabakubipov.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/u1qnl4avnskreo2g7ffb92fmh3/razopasowamuxawe.pdfIn PDF document text
    • http://algarestofos.pnh.pt/js/ckfinder/userfiles/files/69768274733.pdfIn PDF document text
    • http://pcwenhua.com/uploadimg/file/1631737674206014521.pdfIn PDF document text
    • 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_off0000b5a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5A7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cdb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDB9 19500 bytes
SHA-256: d6a8f46b7e1ee00ea9b682e8d6610db0c1b7f60df044947c4ce21d99a10a1ef7
font_02_sfnt_off0000ff90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF90 10248 bytes
SHA-256: 7f616fdea21a18fdaf01db9bed87e236b0183051c725ba9dea71bc237126aafa