Malicious PDF — malware analysis report

Static analysis result for SHA-256 cfb5f6f51261ac9f…

MALICIOUS

PDF

74.9 KB Created: 2021-09-21 02:47:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 425f67737ddee7a348fd641d8092dc9a SHA-1: 3ad9dd1d6d29ca67f32754d9e728d2b5abd98633 SHA-256: cfb5f6f51261ac9f7fa075455b58d0c5c643491472c14cf49a59ba21d8730cf8
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as a malicious PDF by ClamAV and an ML classifier. It contains embedded JavaScript and numerous external URIs, many of which point to potentially malicious PDF files. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a link farm structure, suggesting an attempt to distribute malware or conduct phishing by directing users to various external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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
  • 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 http://uran-berlin.com/userfiles/file/niwezemudovewizoxiluvo.pdf In PDF document text
    • https://xulynuocphangiathinh.vn/images/pic/file/783410778.pdfIn PDF document text
    • http://tnmetalworks.com/images/files/24660006470.pdfIn PDF document text
    • https://xn--nmqu14inmf.com/upload/files/niberofug.pdfIn PDF document text
    • http://scea.edu.mn/ckfinder/userfiles/files/folusanexevozadobig.pdfIn PDF document text
    • http://geoplan.su/userfiles/file/73383946705.pdfIn PDF document text
    • http://bearings.vn/images/ckeditor/files/kakezumegigimolusamevuki.pdfIn PDF document text
    • http://ndt-tl.ru/upload/file/gusefefiwagidufeb.pdfIn PDF document text
    • http://swancentive.com/cote_dor_import/admin/ckfinder/userfiles/files/37101625658.pdfIn PDF document text
    • http://www.ettermanenterprises.com/ckfinder/userfiles/files/gutidamez.pdfIn PDF document text
    • https://activepymes.com/pub/file/vufevupobulalizufe.pdfIn PDF document text
    • http://xn----7sbakif2a3azdub.xn--p1ai/admin/ckfinder/userfiles/files/mudulojezuwej.pdfIn PDF document text
    • http://automsystem.com/UploadFile/file/20210910143413662.pdfIn PDF document text
    • http://residencecarlofelice.com/userfiles/files/649804181.pdfIn PDF document text
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613f053d913de---dikidomixigunu.pdfIn PDF document text
    • http://timatey.kz/wp-content/plugins/super-forms/uploads/php/files/0f0fq9rho700aqcii6oti04bb1/26475184471.pdfIn PDF document text
    • http://josepholszowka.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/48451882598.pdfIn PDF document text
    • http://biswasi.com/userfiles/files/xufugus.pdfIn PDF document text
    • http://yuanjen.com/ckfinder/userfiles/files/kadawodawekuxobulumiwit.pdfIn PDF document text
    • http://albarossa.jp/js/upload/files/36459020044.pdfIn PDF document text
    • http://webursitet.org/Files/file/39705642215.pdfIn PDF document text
    • http://website-design-company.in/dev3/damodar/ckfinder/core/connector/php/userfiles/files/puzerawewid.pdfIn PDF document text
    • http://kidneytracker.com/ckfinder/userfiles/files/nosopigukojalugedixupop.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=how+to+restore+calendar+events+on+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_off0000c15a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC15A 17040 bytes
SHA-256: 2ec5459c417698f18c2984f61df82f1a07a00a43c4b19f7ddf9a5bbe49a8550b
font_01_sfnt_off0000ed92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED92 10508 bytes
SHA-256: c74b7c74eefdb4c9331673331124afdd06f4080b9837331e27a32f10ae5e7f59
font_02_sfnt_off000105a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105A3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1