Malicious PDF — malware analysis report

Static analysis result for SHA-256 3550acbf9f6252dc…

MALICIOUS

PDF

80.0 KB Created: 2021-09-07 08:58:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a21644d04c3648a3f3d327699dec0b93 SHA-1: 812384f42fa74472ed8fc2ce897390e8b8ad20b0 SHA-256: 3550acbf9f6252dca2219b92090a44ce441a5f0567f7ab55be29d2c43e04f7ed
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as a phishing trojan and ML classifiers indicated maliciousness. Heuristics identified it as a link farm containing numerous URLs pointing to compromised WordPress sites and disposable hosting, suggesting an attempt to redirect users to malicious content. While no scripts were explicitly extracted, the nature of the link farm and the PDF format suggest potential for embedded JavaScript to facilitate the redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ddcd5c9e212---zaliluxor.pdf In PDF document text
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/16084024cd1842---71111919237.pdfIn PDF document text
    • http://aceonlinementors.com/userfiles/file/dipovutiwosaxoj.pdfIn PDF document text
    • http://allycatering.com/userfiles/82982908977.pdfIn PDF document text
    • https://kawanmto.net/contents//files/81681983266.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/446b17613f8ded77f3c2f9ee449480d5/jaligalegonivu.pdfIn PDF document text
    • https://www.oasipizza.it/wp-content/plugins/formcraft/file-upload/server/content/files/16094040965039---womike.pdfIn PDF document text
    • https://yziact.fr/wp-content/plugins/super-forms/uploads/php/files/o4ti0h7qbeb8fomgbcks9gpe48/34414287337.pdfIn PDF document text
    • http://smflow.in/admin/uploads/file/talebibexabodopobozi.pdfIn PDF document text
    • http://miraesusan.com/ckupload/files/38025732143.pdfIn PDF document text
    • https://dananeye.com/uploads/files/202108201521459035.pdfIn PDF document text
    • http://agarimo.com/archivos/archivos/56407862945.pdfIn PDF document text
    • http://pet.nfe.go.th/m_site/ckfinder/userfiles//files/70297988042.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c97d280a683---93989544035.pdfIn PDF document text
    • https://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/0fb18c3327b3a69459182b259c2a7700/tizanejajefuvabisopefoxa.pdfIn PDF document text
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/1d9d934db258db3c2050d3f1151914ad/27309546457.pdfIn PDF document text
    • https://airbays.com/userfiles/file/refepugeg.pdfIn PDF document text
    • https://pametnidom.hr/pametne_kuce/userfiles/file/63828801864.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/5b1c89a01ea08b1bb47290f229d8d72e/lamurezuwozavagipena.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16109f23b27e1e---93270004232.pdfIn PDF document text
    • http://zulassungsservice4you.de/bilder/file/bisodimizupazisuv.pdfIn PDF document text
    • http://anapharmata.hu/ckfinder/core/connector/php/files/55632022003.pdfIn PDF document text
    • https://amitadevnani.com/userfiles/file/rabul.pdfIn PDF document text
    • https://autoskola-scp.com/files/29149926244.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=bd+govt+calendar+2019+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_off0000d0f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0F8 18332 bytes
SHA-256: 840369236574c9570fd09337bac76c0ce1c497b663c0c9f8311bf86d0db95ae0
font_01_sfnt_off000100e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100E8 11116 bytes
SHA-256: 7e82d0d8e982fd2ef9395f0503c35f8a97d4329ccd998805c2773e9fca49ee76
font_02_sfnt_off00011aed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1