Malicious PDF — malware analysis report

Static analysis result for SHA-256 e4b836dfb71a9350…

MALICIOUS

PDF

116.0 KB Created: 2021-09-02 00:20:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 86e8e687744c95277d2ed24f7bff9800 SHA-1: 01e4810b71e37b43df43411151c1f90d11aa0cf5 SHA-256: e4b836dfb71a9350cad19547f7779595dd7502f716e415d56a224662b49115c0
156 Risk Score

Malware Insights

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

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The PDF structure and embedded URIs strongly suggest it's part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9967

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://irlanc.ru/uplcv?utm_term=looking+glass+theory+sociology PDF link annotation
    • http://zulassungsservice4you.de/bilder/file/bisodimizupazisuv.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/gofuk.pdfIn PDF document text
    • http://capitolmetrophysicaltherapy.com/userfiles/file/64247019235.pdfIn PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/11583465525.pdfIn PDF document text
    • http://cattaneoarchitetti.it/userfiles/files/vumewerefevifapekuwiluzaj.pdfIn PDF document text
    • http://chapraptti.org/userfiles/file/78027721363.pdfIn PDF document text
    • http://bertoniamministrazione.it/bertoni/public/file/dekimujoxavar.pdfIn PDF document text
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/160778536d7158---62581277173.pdfIn PDF document text
    • http://school19-zav.ru/userfiles/file/32784872879.pdfIn PDF document text
    • https://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/8c778f62d97d1383e0cb1298e94a9ab6/gamagatufinudisumowu.pdfIn PDF document text
    • http://gandolfiarchitetti.com/userfiles/files/38000808306.pdfIn PDF document text
    • http://seibyou-koujien.com/files/files/66519239751.pdfIn PDF document text
    • https://alternatifhirdavat.com/upload/ckfinder/files/11098728017.pdfIn PDF document text
    • http://minerva-collection.net/files/files/zujodowugerunukexawed.pdfIn PDF document text
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a29211767eb---lugezitapuxabegi.pdfIn PDF document text
    • https://www.ideaklinik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160852daac70a6---54992809275.pdfIn PDF document text
    • https://afriqueitnews.com/wp-content/plugins/super-forms/uploads/php/files/588c76cc96d8d2d4f76e287fda7d53cb/32259909821.pdfIn PDF document text
    • http://highlandlynxotic.com/clients/7/73/73cf6ae24f8ea70eb1cbac1dff6b0f9e/File/joripiwilozilizolodem.pdfIn PDF document text
    • https://thietkewebseo.com/webroot/img/files/nadababovowevofojuwopux.pdfIn PDF document text
    • https://bustotoronto.com/userfiles/file/fomebuwaxugukakukoka.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160ba5283b8965---befebopanavikufuda.pdfIn PDF document text
    • http://119hero.kr/userData/board/file/90953124564.pdfIn PDF document text
    • https://b2b-intelligence.it/uploads/file/jozuganejenugunikesapuv.pdfIn PDF document text
    • http://porpora.biz/imagenes/imagenes_contenidos///riripi.pdfIn PDF document text
    • http://ithalattagarantibelgesi.com/resimlerfiles/xusilofalukajiguwumobuwi.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_off00015cc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15CC9 19308 bytes
SHA-256: b6f815ac14b5839104bec92f4927b4288b8a61f23ab76ccf37a40fcfba5a2025
font_01_sfnt_off00018e5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18E5D 10672 bytes
SHA-256: 19cb57d5276b86581805e3cd50a7e0defe29267820ea692900779573b730501d
font_02_sfnt_off0001a6d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A6D5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1