Malicious PDF — malware analysis report

Static analysis result for SHA-256 83411b1afdf9917c…

MALICIOUS

PDF

78.6 KB Created: 2021-09-08 12:06:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: bc0ab73cd77220c8a94ae7d9c91f5540 SHA-1: 89d27d9a5f3a3d13c626cfe9d5080e1855c765be SHA-256: 83411b1afdf9917c8f9ec12eb1201ca0e1e81655870e53762cc96c13abd3bf45
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a link farm with numerous URLs, many pointing to compromised WordPress installations, suggesting an attempt to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware distribution lure, likely initiated via spearphishing.

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 http://brighterhealthcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/6e6pvmng35kmkoetsl0k7hfra8/nujekukavuberuvu.pdf In PDF document text
    • https://twr1115.net/files/fckeditor/file/89249748250.pdfIn PDF document text
    • https://markeishahall.com/wp-content/plugins/super-forms/uploads/php/files/2e4d35d8bd355e37a1b9dc06a9e57f8f/pirozuvoxupe.pdfIn PDF document text
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/3dof54rtj5f5gkcku5o4flntgp/vezefabete.pdfIn PDF document text
    • http://csc0898.com/userfiles/file/20210626195504_fpto27.pdfIn PDF document text
    • https://actorconseil.com/files/file/kunibixose.pdfIn PDF document text
    • https://visualmotion.nl/uploads/file/jelobex.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c01d15e7449---21005217965.pdfIn PDF document text
    • http://eg-connect.com/uploads/editorfiles/file///99397699598.pdfIn PDF document text
    • https://gdr.co.il/wp-content/plugins/super-forms/uploads/php/files/c4965146da0cf63c29dba456d00b45e5/62588388465.pdfIn PDF document text
    • https://alarrabnews.com/images/content/content/file/wokowa.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/b171b3caf5773596d97137aed99ca99f/lulajimokikesodipoxuto.pdfIn PDF document text
    • http://high-keenltd.com/userfiles/file/14239282059.pdfIn PDF document text
    • http://suseefinance.com/userfiles/file/loxetuwobusipepivu.pdfIn PDF document text
    • http://montpellier-businessplan.fr/mbp/upload/images/images/upload/ckfinder/10324457887.pdfIn PDF document text
    • http://dulichtantai.com/files/uploaded/files/vosawijotiwox.pdfIn PDF document text
    • http://workcoop.org/fckeditor/userimages/file/20210606195553.pdfIn PDF document text
    • http://dongsachhanoi.com/webroot/img/files/38149295632.pdfIn PDF document text
    • http://martom24.pl/martom/userfiles/file/7441149745.pdfIn PDF document text
    • http://phubozena.pl/userfiles/file/fibipajetogofida.pdfIn PDF document text
    • https://proektasis.gr/admin/spaw2/uploads/files/48649369283.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/160fc9a1164abc---dubejokunalo.pdfIn PDF document text
    • http://www.adatechotomasyon.net/wp-content/plugins/formcraft/file-upload/server/content/files/16085618fa1011---javisal.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/1609d4cc7a64a4---67667251668.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=a+practical+english+grammar+%284th+edition%29+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_off0000c835.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC835 19228 bytes
SHA-256: 1e398c763236cc8aeb47e273a9666b7162d1112c9d7a8dd58cfb39422762cd1e
font_01_sfnt_off0000fa58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA58 11284 bytes
SHA-256: 617294bea315b56c1bd88b76b4c887cbc10a30963f023fa8be6a83d62a891c2a
font_02_sfnt_off000114a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114A3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1