Malicious PDF — malware analysis report

Static analysis result for SHA-256 90ac1e428aae8a28…

MALICIOUS

PDF

79.2 KB Created: 2021-09-12 18:12:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: fe93b7047e2cbe36af3100b3ada49f1d SHA-1: d509692b2103e6a6720617771f914e57a300dc10 SHA-256: 90ac1e428aae8a28f7258dc25c0bcd5a27eb265d0ab1ab78c7710b38fb282bdb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm with numerous URLs pointing to unknown PDF files hosted on various domains, some of which are identified as compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. The document body is heavily obfuscated and contains no readable content, suggesting it's designed purely for redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • 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 https://floridainvestment.cz/files/file/2154645226.pdf In PDF document text
    • https://widerbet.pl/userfiles/file/94984149459.pdfIn PDF document text
    • http://cuspsurgeons.com/userfiles/file/6234931354.pdfIn PDF document text
    • https://novsport.com/content/File/wovozevomuliwu.pdfIn PDF document text
    • http://gainliving.com/upload/editor/file/53674008663.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/1613023f49e3b9---44090078060.pdfIn PDF document text
    • http://seattlebestteriyaki.com/uploads/files/14283903823.pdfIn PDF document text
    • https://manuscripthandler.com/userfiles/file/surigamirogafitovusug.pdfIn PDF document text
    • http://simsoncantho.com/userfiles/file/xeguwagamexilofedikafit.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/16138c2c9af3cd---44264066297.pdfIn PDF document text
    • http://citygclub.com/ckupload/files/12601177148.pdfIn PDF document text
    • http://sl-light.ru/design/img/upload/file/78779215721.pdfIn PDF document text
    • https://art-gallery.mn/uploads/files/jatuzazuvit.pdfIn PDF document text
    • http://ryanoomen.nl/uploadimages/files/vezififezudasis.pdfIn PDF document text
    • http://maslatalaia.com/userfiles/file/77954204549.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/161370bc74b238---1720237999.pdfIn PDF document text
    • http://orbitsecurity.qa/pro_mvp_tech/uploads/file/23326941245.pdfIn PDF document text
    • http://szerecsengyogyszertar.hu/editor_up/davari.pdfIn PDF document text
    • http://kezmosas.hu/files/file/72274636317.pdfIn PDF document text
    • http://thedewakohchang.com/image/upload/File/5584650914.pdfIn PDF document text
    • https://rubenoferro.com/userfiles/file/92692135877.pdfIn PDF document text
    • http://kdekdyjak.cz/data/49885013547.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/henjnrffur4iam1injj7c15c77/75042960848.pdfIn PDF document text
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/e00809fc121cc863c0de370ebba88d42/mojevumemuwer.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=car+x+drift+online+pcPDF 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_off0000ce95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE95 10580 bytes
SHA-256: abd50f1fd57a87ef3b4032876a93ef3ff5f0377592b4ee0187e7bccd294f02ee
font_01_sfnt_off0000e6ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6CE 18520 bytes
SHA-256: 2a28624519eafd2d518b0e92ab3d14d216428b8b0541156962ed6ed4fef25c39
font_02_sfnt_off00011727.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11727 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1