Malicious PDF — malware analysis report

Static analysis result for SHA-256 f53f6a2335306a79…

MALICIOUS

PDF

63.7 KB Created: 2021-09-27 22:31:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 47883cbbc30bfd5eae6eb44cabced572 SHA-1: 4ce858606790517af8ed862f5b56d33a7dc4e33d SHA-256: f53f6a2335306a79928a4a3e61794ccf1a468907161b1e5155eebed397dea3d4
162 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. Several heuristics indicate the document is part of a link farm, with many URLs pointing to external PDF files hosted on potentially compromised websites. ClamAV detection and ML classification further support its malicious nature, suggesting it's a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.5661

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.
  • 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
  • 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.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/161342902185f7---rojefezarupenaditovevux.pdf In PDF document text
    • http://ekachaiguitarist.com/ckfinder/userfiles/files/budukabidudesutozaloked.pdfIn PDF document text
    • https://sharjahcements.com/images/bulk_images/files/ferixezoxidus.pdfIn PDF document text
    • http://ark-mr.com/data/home/qxu2063190031/htdocs/uploadfile/files/tuperekuworuxozawatasa.pdfIn PDF document text
    • http://maezawa-jidousha.com/js/upload/files/fibukujawon.pdfIn PDF document text
    • http://ankaraeksioglu.com/resimler/files/lolupakadigavamuboled.pdfIn PDF document text
    • http://villalapinetafavignana.it/userfiles/files/21458226269.pdfIn PDF document text
    • http://cps-mbstu.edu.bd/app/webroot/js/ckfinder/userfiles/files/75283318882.pdfIn PDF document text
    • https://nangluongvada.com/uploads/files/16628482508.pdfIn PDF document text
    • http://mesterteto.hu/userfiles/file/kofiparexisabojatom.pdfIn PDF document text
    • http://sibinetweek.ru/userfiles/file/milup.pdfIn PDF document text
    • http://orthodoxnews.us/file/bufewovepovanigunur.pdfIn PDF document text
    • http://vswet.ru/f/jopokofoxonijukepabiwepip.pdfIn PDF document text
    • http://arqing.es/ckfinder/userfiles/files/50378899454.pdfIn PDF document text
    • http://leadingedgecorporate.com/user_images/file/sodefexediv.pdfIn PDF document text
    • https://sporyolu.com/resimler/files/vesopifuromadol.pdfIn PDF document text
    • http://donovaly-ubytovanie-safran.sk/web/userfiles/file/zekeviruwobapugamaveneba.pdfIn PDF document text
    • https://www.utn.ac.cr/sites/default/files/files/22347938882.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/60e9477326e9a7cdffc3b30dab2369ed/25610939174.pdfIn PDF document text
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/2449bd252363d60f0fa4fd0c7669e441/9433561171.pdfIn PDF document text
    • http://gojjang.com/uploads/files/87554744306.pdfIn PDF document text
    • https://foodvellythailand.com/upload/files/mufodovodewabojubelupa.pdfIn PDF document text
    • https://thuhuonglacquer.com/uploads/news_file/minave.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=fundamentals+of+plasma+physics+bittencourt+solutions+manualPDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b041.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB041 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c858.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC858 11216 bytes
SHA-256: 0794b14e683d50b54c9c99fc8973169f4a2ff791a0b4ee60420247f964286cbe