Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4dbf576799a72e7…

MALICIOUS

PDF

87.3 KB Created: 2021-10-08 00:32:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: f12ae7ca6b331220efd7cda32ae9738e SHA-1: 6a99cba1c9feb3497cc55631202c56ea0e5b7a1e SHA-256: a4dbf576799a72e70c775dbf96a203f41dc97fb87dcf57f7b2e2466eaa4da4a3
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs pointing to various domains, many of which appear to be associated with compromised CMS uploads or disposable hosting. The ML classifier strongly indicates maliciousness, and the heuristic firings confirm the presence of a link farm designed to redirect users. No scripts were extracted, but the primary attack pattern involves luring users to external, potentially malicious, websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

Heuristics 5

  • 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://nomylo.ru/uplcv?utm_term=synthesize+meaning+in+tagalog PDF link annotation
    • https://ngenadmin2.nextgenphotosolutions-beta.com/app/webroot/files/file/38562340911.pdfIn PDF document text
    • http://kanalizace-ul.cz/userfiles/file/wumasisara.pdfIn PDF document text
    • http://biondiairsystem.it/userfiles/files/guforedorupalunulopenoz.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d0f1e203d4---47173664868.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/a44c6a67fd3d51eb34a97f4ed140fe9e/77994967561.pdfIn PDF document text
    • http://www.wcd.com.tw/ezadmin/ckfinder/userfiles/files/1012752619.pdfIn PDF document text
    • http://www.madiran-cruduparadis.fr/ckfinder/userfiles/files/17742244941.pdfIn PDF document text
    • http://vakantie-noordlimburg.nl/ckfinder/userfiles/files/77678947197.pdfIn PDF document text
    • http://7seapharmtech.com/Uploadfiles/files/jebovot.pdfIn PDF document text
    • http://feldbach-tourismus.at/files/vejeg.pdfIn PDF document text
    • http://www.fd.ntou.edu.tw/ckfinder/userfiles/files/mekexojigilejujibaz.pdfIn PDF document text
    • https://webshopplus.nl/app/webroot/files/userfiles/files/32507640769.pdfIn PDF document text
    • http://eros-arena-reutlingen.de/eros/userfiles/file/88378630053.pdfIn PDF document text
    • http://metrocars.london/survey/userfiles/files/62531808193.pdfIn PDF document text
    • https://autonoleggioassereto.com/file/80692989358.pdfIn PDF document text
    • https://gmt-tw.com/app/webroot/userfiles/files/43994800646.pdfIn PDF document text
    • https://primer-spb.ru/files/files/45296569664.pdfIn PDF document text
    • http://xn----7sbab1bcaqplb0ccyi9d.xn--p1ai/files/file/bojegekolufekoximematamid.pdfIn PDF document text
    • http://caratow.be/userfiles/file/linukir.pdfIn PDF document text
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ddab12f88a---85262140071.pdfIn PDF document text
    • https://icon-studios.com/userfiles/file/sefuvibejiwe.pdfIn PDF document text
    • https://pharma-tools.pl/galeria/file/2459112494.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_off0000ec90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC90 19896 bytes
SHA-256: ef309a7225af4a006dcb4051c495a9c8f158763dae6aaacb7967836cb9476437
font_01_sfnt_off00011f81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F81 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013798.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13798 10704 bytes
SHA-256: 96ea76046b48cedc0913319ab5b34f9c34decc8b979fb925aebf4ea9e37d2aff