Malicious PDF — malware analysis report

Static analysis result for SHA-256 f84857733161c253…

MALICIOUS

PDF

81.9 KB Created: 2021-09-19 05:42:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 9ca4d577e16e4f5fd2a1c72ab5115641 SHA-1: e18821e73b66547dba7cd80de008a7a1f5697220 SHA-256: f84857733161c2533dc68893dcf153132dc77afd4d4f16aaf34df9dabbac8fa7
164 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The sample was identified as malicious by a machine learning classifier and ClamAV, indicating a high likelihood of malicious intent. It contains embedded JavaScript and a link farm pointing to multiple unknown PDF files hosted on various domains, suggesting it's designed to redirect users to potentially malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports the use of compromised or disposable hosting for distributing malicious content.

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 https://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/783c5c5a76d0cc4fa36e3172971cfcd5/99843713321.pdf In PDF document text
    • http://langmoon.jp/js/upload/files/88606800529.pdfIn PDF document text
    • https://yuvasarkar.org/userfiles/file/vuvikenadesug.pdfIn PDF document text
    • https://www.sesc-am.com.br/Selecao/ckfinder/files/35968710263.pdfIn PDF document text
    • http://special-pharma.com/upload/files/55404313061.pdfIn PDF document text
    • http://noithatdangcap.vn/app/webroot/uploads/files/23842864331.pdfIn PDF document text
    • http://omatsuri.kr/data/userfiles/files/joboxukozep.pdfIn PDF document text
    • http://master-stroi76.ru/userfiles/file/velefok.pdfIn PDF document text
    • https://thokhoavietnam.com/upload/files/xigamorogivopodijodegeli.pdfIn PDF document text
    • http://boilerservis.ru/uploads/files/pavelabubifativubusezakis.pdfIn PDF document text
    • https://soi.icami.mx/ckfinder/userfiles/files/72009547553.pdfIn PDF document text
    • http://steelbo.com/uploads/admins/u0/files/20210911082132.pdfIn PDF document text
    • http://jmvlpslimited.com/ci/userfiles/files/zavezubefenejileva.pdfIn PDF document text
    • http://career-id.org/ckfinder/userfiles/files/makunuwusipagafuxawax.pdfIn PDF document text
    • https://supportsystemsvainc.com/home/ssvi/public_html/ckfinder/userfiles/files/71488657394.pdfIn PDF document text
    • https://condicionamentofisico.com/arquivos/file/susezozoroloj.pdfIn PDF document text
    • https://ducthai.vn/userfiles/file/wugugopimiwesizeto.pdfIn PDF document text
    • https://peintures-descours.fr/fichier/files/vevanisimefofasokotovi.pdfIn PDF document text
    • https://ferdavagnar.is/images/fck/file/dazurexituf.pdfIn PDF document text
    • http://winhazel.com/indigo/ckfinder/userfiles/files/32849042532.pdfIn PDF document text
    • https://windfreeklima.com/upload/ckfinder/files/68680692761.pdfIn PDF document text
    • https://stonebuild.bg/f/uploads/files/99192955622.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/292986808cc168cf6c6108b622df3072/sadawet.pdfIn PDF document text
    • https://travelworld.ro/userfiles/file/65055288830.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bc796b6a99---45414057118.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=ear+spy+androidPDF 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_off0000de34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE34 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f64b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF64B 10208 bytes
SHA-256: 50ca78db4eb1434a2d94ffa35eb63f76ade8dcfa0a5688958230e1590e330ec9
font_02_sfnt_off00010d36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D36 17564 bytes
SHA-256: f3e799469629e58c0cd8bc227d19ca9ea62bbd93cb496eb9b2f9cdef2c664671