Malicious PDF — malware analysis report

Static analysis result for SHA-256 b991a45532b196ba…

MALICIOUS

PDF

70.1 KB Created: 2021-09-15 13:11:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: bf6794fa2c4a452a24c2adf29c4a9fc1 SHA-1: 3a116128b5e3b9de598ea7a2c1f6c8e8eda303da SHA-256: b991a45532b196ba7cb8f443f07cc321adc95160857bf2b37209bd1af9e1eb90
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags this behavior, suggesting the document's purpose is to distribute traffic to potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://toanthinh.vn/webroot/img/files/44880210572.pdf In PDF document text
    • http://worldwidestationeryholdings.com/files/file/loguduluxugusedofuj.pdfIn PDF document text
    • https://ekoelprom.pl/public/images/editor/file/14499707867.pdfIn PDF document text
    • http://vizugy.hu/uploads/files/lovawesili.pdfIn PDF document text
    • http://kitpaisal.com/mypicture/file/93111141008.pdfIn PDF document text
    • http://beiks.info/public/file/39636253331.pdfIn PDF document text
    • http://www.juniorcollege.cl/ckfinder/userfiles/files/gufimafosinasugexewidida.pdfIn PDF document text
    • https://www.spitalmoldovanoua.ro/ckfinder/userfiles/files/59865752530.pdfIn PDF document text
    • http://rybarict.cz/webpagebuilder/ckfinder/userfiles/files/wofusax.pdfIn PDF document text
    • https://peisheng.org/uploads/ckfiles/files/613f92a1b5b32.pdfIn PDF document text
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16141187938147---bobunifakovolawu.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613607facc0e8---33910181152.pdfIn PDF document text
    • https://eniedu.com/data/file/20210912030239.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/91311535808.pdfIn PDF document text
    • https://grootformaatspandoeken.nl/userfiles/file/9265809484.pdfIn PDF document text
    • http://goldia.cz/data/file/85782716520.pdfIn PDF document text
    • http://qamsar.org/userfiles/files/59548270199.pdfIn PDF document text
    • https://www.aironface.com/wp-content/plugins/super-forms/uploads/php/files/89a711d1e427b44d87f04523f7528c7a/pejorimaloxadesuf.pdfIn PDF document text
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/f6bcc3f7d0e8c43189b44eaa0e1564b5/kipebajumotefoko.pdfIn PDF document text
    • https://coherence.cz/userfiles/file/gilazotagamemudisedemusig.pdfIn PDF document text
    • http://horizonpestservices.com/userfile/21356275195.pdfIn PDF document text
    • http://studiotecnicomartani.eu/userfiles/files/bimerinuzafuxanukewufepaf.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=watch+class+action+park+documentary+online+freePDF 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_off0000b267.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB267 11184 bytes
SHA-256: f938eb8bba64cd69af344a75a858dbfdafd6a832c6032baaa2d9f662d30c9dca
font_01_sfnt_off0000cc6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC6F 15060 bytes
SHA-256: 067eea6536ca5268ad4eac2cff58cd4306ae104ef38d89b67a16b18bcb73cfa7
font_02_sfnt_off0000f275.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF275 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1