Malicious PDF — malware analysis report

Static analysis result for SHA-256 d404b194cdbe551a…

MALICIOUS

PDF

87.0 KB Created: 2021-09-23 10:15:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 4a60cab400d3118a7cb1c0e49b5c9c56 SHA-1: a8ef5447e1f37f7715fe981fccdefa36f9123a47 SHA-256: d404b194cdbe551abcdcf6f1a9b86998aba61a9ed6ebb533e06eb6d4ff33dea4
196 Risk Score

Malware Insights

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

The PDF document contains multiple links to external resources, many hosted on compromised or disposable domains, suggesting a link farm designed to redirect users. The 'SE_BROWSER_INSTALL_LURE' heuristic indicates the document's content likely prompts the user to install a browser extension or update, a common social engineering tactic. ClamAV detection as 'Pdf.Phishing.Trojan' further supports a malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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 http://texinpack.com/uploadfile/file///2021090400413556.pdf In PDF document text
    • https://tiklatakip.com/calisma2/files/uploads/pujaruzadusim.pdfIn PDF document text
    • http://nutranghongngoc.com/media/ftp/file/25607727545.pdfIn PDF document text
    • https://oriontradecom.com/ckfinder/userfiles/files/wekokenirulekinulit.pdfIn PDF document text
    • https://opescom-store.com/uploads/FCK_files/file/rulev.pdfIn PDF document text
    • https://www.karavanlakesfet.com/wp-content/plugins/super-forms/uploads/php/files/0f8ed2e29c61a45c048f261581dc27d1/dapesedofume.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fd1ddc25a8---notexezofelix.pdfIn PDF document text
    • https://strategieb2b.com/userfiles/file/81741813120.pdfIn PDF document text
    • http://rhondadejean.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/foxewonebefirem.pdfIn PDF document text
    • https://dom4m.by/userfiles/files/75085798029.pdfIn PDF document text
    • http://tmkb.org.tr/ckfinder/userfiles/files/kedelusolupebev.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a6e6b8ef74---kimogopasejinezu.pdfIn PDF document text
    • http://augustaelectricalwork.com/editorData/file/piregek.pdfIn PDF document text
    • http://rasciindia.com/firetech/ckupload/files/83659607978.pdfIn PDF document text
    • http://mywayrtk.org/userfiles/file/37428784069.pdfIn PDF document text
    • http://kortennis.co.kr/B/ck/ckfinder/userfiles/files/wurux.pdfIn PDF document text
    • https://hobbyschuurtje-webwinkel.be/images/userfiles/file/59712396592.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=like+a+boss+ytsPDF 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_off0000ed36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED36 10156 bytes
SHA-256: ffbf98230e242e2c221971b566d1f90df49d8c3bfa0c937c99d98d79e55045e7
font_01_sfnt_off00010423.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10423 19512 bytes
SHA-256: c21f8b95d9ed289b43336813f4394875fa307a3c28ca5d669bf21a64e5764cda
font_02_sfnt_off00013758.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13758 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1