Malicious PDF — malware analysis report

Static analysis result for SHA-256 88c83b702109240a…

MALICIOUS

PDF

79.4 KB Created: 2021-09-13 17:44:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 95ec2b6b85f5c28c90df7fc7157f7caf SHA-1: f2f7c1cd182d4f8cdbc0fb6bf35f621a7ed45b5f SHA-256: 88c83b702109240ad8b962602758a0ade8a414c96db8c21bd502e7c43038de4a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs that form a link farm, with several pointing to compromised WordPress sites or disposable hosting. The primary purpose appears to be directing users to potentially malicious or phishing websites, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://cructi.ru/uplcv?utm_term=can+android+run+windows PDF link annotation
    • http://bukharajohnscreek.com/sites/default/files/file/21582238983.pdfIn PDF document text
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139108040487---51295902998.pdfIn PDF document text
    • http://dxline.eu/userfiles/file/41706264520.pdfIn PDF document text
    • http://debsecond.net/UserFiles/File/89717672878.pdfIn PDF document text
    • https://tidaksusah.com/contents/files/96537880360.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613977715f337---veruse.pdfIn PDF document text
    • http://vce34.ru/attachments/file/polefusigowuze.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/94457379800.pdfIn PDF document text
    • http://portakalweb.net/home/portakal/public_html/ckfinder/userfiles/files/labijikenes.pdfIn PDF document text
    • https://wspaperbag.com/userfiles/file/18335839229.pdfIn PDF document text
    • https://sainaudit.mn/File/26238038082.pdfIn PDF document text
    • https://corianderedmonton.com/ckfinder/userfiles/files/jiwofebaninarelitigi.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ab09b2754e---29468945498.pdfIn PDF document text
    • https://cowichanseniors.ca/userfiles/file/teleremuku.pdfIn PDF document text
    • http://timavoshipsupply.it/userfiles/file/wujewatifavubizosuxima.pdfIn PDF document text
    • http://alda.pl/ckfinder/userfiles/files/gigibejagole.pdfIn PDF document text
    • http://sumbulefendiegitimvakfi.com/resimler/files/59897222000.pdfIn PDF document text
    • https://rrr71.ru/upload_picture/80590885826.pdfIn PDF document text
    • https://techinnsrl.com/writable/public/userfiles/file/42330898296.pdfIn PDF document text
    • http://e-instar.com/userfiles/file/20719755201.pdfIn PDF document text
    • https://typeone.com.my/ckfinder/userfiles/files/67365114056.pdfIn PDF document text
    • https://webkapper.nl/ckfinder/userfiles/files/befevitunutalomewa.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_off0000d355.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD355 10184 bytes
SHA-256: 663dfae6fc51f94cc85a334255b71642aae31f26cea5cfc97ec1b8eb6a707333
font_01_sfnt_off0000ea4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA4C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001025e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1025E 17800 bytes
SHA-256: 749683a1014b731b6f809ece3a2525527a6eef9b8e646fd1b47d225f22f0d0c2