Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d4c8e3daba65778…

MALICIOUS

PDF

70.0 KB Created: 2021-09-30 23:34:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 0ba39a453bf170fcf33d3e1fe49ac101 SHA-1: 8661c6d0b458fc06698c0f2ad4d1c7dd690805b3 SHA-256: 8d4c8e3daba657785d5c5822e5b0c8b46a02714d314d93500c114cf95fe595ed
164 Risk Score

Malware Insights

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

This PDF contains embedded JavaScript and multiple external URIs pointing to compromised WordPress sites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to exploit vulnerabilities or trick the user into downloading a secondary payload. The presence of a link farm on disposable hosting further supports a malicious purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://duet-czluchow.pl/userfiles/file/82797451191.pdf In PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/tazixawatilodubasurazavuv.pdfIn PDF document text
    • http://insightonafrica.in/userfiles/file/9853941028.pdfIn PDF document text
    • http://kroonzuivel.nl/ckfinder/userfiles/files/39149856583.pdfIn PDF document text
    • http://opgzvh.hr/upload/file/76463488864.pdfIn PDF document text
    • http://www.ssc-ras.ru/ckfinder/userfiles/files/18363261537.pdfIn PDF document text
    • http://marikitaberbagi.com/userfiles/file/levidefudi.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613188a442a79---8452123302.pdfIn PDF document text
    • https://abyway.lv/images/ck_images/files/kunobunape.pdfIn PDF document text
    • https://zifu-tech.com/app/webroot/userfiles/files/5636432620.pdfIn PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/16145a3e44b44e---fagixudarikozewudab.pdfIn PDF document text
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/0cbq285jisnrt7r4c6i63fss0f/22685922970.pdfIn PDF document text
    • http://mamnonhieutrung.edu.vn/ckfinder/userfiles/files/4123945990.pdfIn PDF document text
    • http://bogaarchitetti.it/userfiles/files/76103430662.pdfIn PDF document text
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/u6k156vo37d4qupmfur3nihp20/88686189123.pdfIn PDF document text
    • http://harringtonandlombardi.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/biwizirugedewabovojoro.pdfIn PDF document text
    • https://i-try.tw/upfile/files/2021/09/09/18179873117.pdfIn PDF document text
    • http://albarossa.jp/js/upload/files/vibowulepikizeleburimewix.pdfIn PDF document text
    • https://artasedanasingaraja.com/uploadfck/file/busisogubiwuf.pdfIn PDF document text
    • http://thicongdiennuocmiennam.com/uploads/files/31054315694.pdfIn PDF document text
    • http://grafiport.com/userfiles/file/zikosevibosagakejotov.pdfIn PDF document text
    • http://105chers.netsociality.com/upload/files/33440246911.pdfIn PDF document text
    • https://dialogueinpraxis.net/files/docs/36942701492.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612f555377038---24884669414.pdfIn PDF document text
    • http://oshcongregation.com/userfiles/file/55631505189.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=ahsan+ul+bayan+english+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_off0000b3b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3B0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cbc2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBC2 15044 bytes
SHA-256: b0428e66330fd1adcb456c6719d35cbe088df0f1c78d246bd636ece72e3ef87d
font_02_sfnt_off0000f1cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1CC 10792 bytes
SHA-256: 7bb23edf4440bc31e1d339b1c41709d49e11a92d0feb718adf19f869082f83c7