Malicious PDF — malware analysis report

Static analysis result for SHA-256 a479959ed1b51831…

MALICIOUS

PDF

70.7 KB Created: 2021-10-04 10:35:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a749273ff304024dc3acacbbfe4e4808 SHA-1: 4ff7210d2d2738d4011d879e4e9c33693a92d272 SHA-256: a479959ed1b5183182cd9422b3b2d8526b661d313ce9ca94e7e0dba5035d6cc9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised websites or disposable hosting, suggesting a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and link farm behavior are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://ketchas.ru/uplcv?utm_term=how+much+is+61+kg+in+lbs
    • http://dreiseengrundschule.de/files/gujagidisifisomawedujiv.pdf
    • https://chezgregoire.fr/userfiles/55806671245.pdf
    • http://feuerwehr-mittenwalde.de/mediathek/files/ratoxenikukuvimelos.pdf
    • http://ndfeef.com/radiant/mechimobiles/userfiles/files/lewidozejota.pdf
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fd083a0c7c---segivujidawipen.pdf
    • http://kolkandkolkdesign.com/site/data/ws/files/pigoditadonusepona.pdf
    • https://sensiblemachines.com/ckfinder/core/connector/php/files/2965683546.pdf
    • http://jan-fotografie.nl/upload/files/22613854195.pdf
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/461ca0ef9575f3d6a63980788ee5a444/kunusojuxosufixa.pdf
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/2a89fdc01d3d85018cc4ec5c7f19af77/zigipowenujurumegupupimam.pdf
    • http://joyearland.com/ckfinder/userfiles/files/xozuzijukudufiwad.pdf
    • http://cl-metalparts.com/d/files/43608646593.pdf
    • http://moretonassets.net/userfiles/85447349540.pdf
    • http://utcsp.rustyramone.com/uploads/files/86084068808.pdf
    • https://vickers-electronics.co.uk/wp-content/plugins/super-forms/uploads/php/files/a9c3a87f1e266880d12f63260fa1854b/66509461279.pdf
    • http://duet-czluchow.pl/userfiles/file/37447511522.pdf
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/14f0bafe95323cebc00e81975545124a/zoxukojimajazupesedo.pdf
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/1614d97e324b20---gezegogasasomez.pdf
    • http://xn--80aaeiengkwpz6p.xn--p1ai/pub/file/42143622078.pdf
    • http://nhatnguyen.vn/media/ftp/file/guxukovobafuzojekotiwape.pdf
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/9b6bac8b92a282db0dcc0f8c6d8fbebc/13202843870.pdf
    • https://inunekocp.jp/mailmagazine/upload/files/6836429528.pdf
    • http://toyotaquangninh.org/data/dulieu/files/mixekelep.pdf
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/1a4a06499d87bf13d29acaad725b8916/304540247.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b16d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB16D 16792 bytes
font_01_sfnt_off0000c97f.bin
42ee587be3b2b2e3c3ac9905d84be12bb0991675db4ae70dd7e0216732f7653c
pdf-font-stream PDF embedded font (sfnt) at offset 0xC97F 16856 bytes
font_02_sfnt_off0000f4bb.bin
e64e408dc67549cf4c0478b8268a822c50dce53f58a56e8710d3d8ea717e1d21
pdf-font-stream PDF embedded font (sfnt) at offset 0xF4BB 10816 bytes