Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b5fa4d40abf4482…

MALICIOUS

PDF

80.9 KB Created: 2021-09-11 23:04:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 18b794db7802cc5dedb94ad8f79b1996 SHA-1: b67fa5918faeda20b6927f496d5ff6f94a2bdd49 SHA-256: 8b5fa4d40abf448219cf11564961167fa0a4a5b5efab60b2c4b5b0c16e8b0b8b
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. The PDF contains numerous embedded URLs, many pointing to potentially malicious or disposable domains, consistent with a link farm used for distributing further malicious content. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it's designed to redirect users to these external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://aimecostruzioni.it/userfiles/files/71980228808.pdf In PDF document text
    • http://educasters.co/ckfinder/userfiles/files/43281182859.pdfIn PDF document text
    • http://floridadressyourhome.com/uploaded_files/userfiles/files/18032815564.pdfIn PDF document text
    • http://terralis.eu/catalogue_dynamique/file/75598472091.pdfIn PDF document text
    • http://seattledesis.com/fckeditor/file/bilawipag.pdfIn PDF document text
    • http://icaalliance.org/filespath/files/20210910004549.pdfIn PDF document text
    • http://stellarp.com/userfiles/file/38057895004.pdfIn PDF document text
    • https://tunhuaduytan.com/upload/userfiles/files/gususafobunavag.pdfIn PDF document text
    • https://aakritidigitals.com/userfiles/files/wuvufenaredelev.pdfIn PDF document text
    • http://mitcostruttori.it/userfiles/files/vexozemuni.pdfIn PDF document text
    • https://ashleymongolia.mn/uploads/files/13155312976.pdfIn PDF document text
    • http://tugrabilgisayar.net/resimler/files/mejunodavon.pdfIn PDF document text
    • http://steelbo.com/uploads/admins/u0/files/20210905105622.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fc13ae7b9a---zagugafategalenibegavas.pdfIn PDF document text
    • http://studiorestagno.eu/userfiles/files/30989231062.pdfIn PDF document text
    • http://nextlab-semi.com/files/fckeditor/file/47354689119.pdfIn PDF document text
    • http://africareview.in/userfiles/file/jurinidexuxokezudu.pdfIn PDF document text
    • http://22vek-omsk.ru/fck_editor_files/files/jaromamupugurodedulolujo.pdfIn PDF document text
    • http://www.asiacoservice.com/file/files/zenop.pdfIn PDF document text
    • http://bumsnab.ru/uploads/files/45713232363.pdfIn PDF document text
    • http://chiari-web.com/ckfinder/optimist/files/91250558205.pdfIn PDF document text
    • https://unovosti.tv/ckfinder/userfiles/files/53747939412.pdfIn PDF document text
    • https://oriental-kitchens.com/userfiles/files/degoveneziwiwawuxadenov.pdfIn PDF document text
    • http://321eastern-thailand.com/userfiles/files/fupumuturovo.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b571fc474f---4402161162.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=automatic+rain+gauge+typesPDF 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_off0000d70a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD70A 17908 bytes
SHA-256: 7b4e0f042efc55a3a475b9d1b955a3fb9fb1e2bb4df3ab825de2b5cb047db300
font_01_sfnt_off000104e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104E5 10864 bytes
SHA-256: deaee5f4bae6084cb05142cce7866f39198b9cb265e105af8afb5a0424238cc1
font_02_sfnt_off00011e0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E0F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1