Malicious PDF — malware analysis report

Static analysis result for SHA-256 4638136d8fcb7e71…

MALICIOUS

PDF

81.0 KB Created: 2021-09-15 15:53:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f1227a16978243cf944b9d304406c717 SHA-1: e6cf595df24adbc2fd4e13958a17824a9bbf8427 SHA-256: 4638136d8fcb7e7124828804f941d713bc6570ee55564fb812e0d07bc32ae4c3
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to compromised WordPress upload directories or disposable hosting, forming a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect the user to a phishing or malware distribution site. The presence of embedded JavaScript suggests an attempt to execute malicious code within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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
  • 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://copy2d.com/ftp/image/file/94677021049.pdf In PDF document text
    • https://www.aironface.com/wp-content/plugins/super-forms/uploads/php/files/e37d93b2db841575f58a54f29b8fd936/22153682466.pdfIn PDF document text
    • http://buyyoutubecomments.com/ci/userfiles/files/89889936990.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/t9tg0oof9hrdgkt9re4u81ssj3/54243533101.pdfIn PDF document text
    • http://sparan-art.ru/ckfinder/userfiles/files/67801093264.pdfIn PDF document text
    • http://bhartiyambeohari.in/userfiles/file/tonujufuzojedexa.pdfIn PDF document text
    • http://pagyesa.org/userfiles/file/20210914081431.pdfIn PDF document text
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/11138c224828283293c83e3a703074b5/nemagadarok.pdfIn PDF document text
    • http://allier-genealogie.org/File:/30986672751.pdfIn PDF document text
    • https://avukatwebsitesi.trakyasoft.com/upload/files/89833407759.pdfIn PDF document text
    • https://sporyolu.com/resimler/files/35585633303.pdfIn PDF document text
    • https://osiindia.org/ckfinder/userfiles/files/gakapimenab.pdfIn PDF document text
    • http://energy-labels.com/userfiles/file/bolenunex.pdfIn PDF document text
    • http://picart-personal.pl/fckupload/upload/file/78616320413.pdfIn PDF document text
    • http://sydjpg.com/images/upload/file/20210904_041019_196.pdfIn PDF document text
    • https://aahs.givingplan.net/sites/default/files/editor/file/xibowotojasesa.pdfIn PDF document text
    • https://vietnamairlinescorp.org/js/ckfinder/userfiles/files/11916980030.pdfIn PDF document text
    • http://laduses.nl/image/file/32635094298.pdfIn PDF document text
    • http://franzoesischebulldoggen.eu/userfiles/file/fozijero.pdfIn PDF document text
    • http://galeriejacqueselbaz.com/userfiles/file/givifufa.pdfIn PDF document text
    • http://markfarolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/lopavokaliletimiwinemi.pdfIn PDF document text
    • https://xenonsvjetla.com/files/sabozusomunexizapedu.pdfIn PDF document text
    • https://www.hsbofmn.com/ckfinder/userfiles/files/latezuwuxavaxemilimamufi.pdfIn PDF document text
    • https://cahayamimpi1.com/contents/files/jitoxexinomifikorejom.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=mario+64+luigi+model+downloadPDF link annotation
    • https://www.assessment.unibe.ch/app/webroot/js/ckfinder/userfiles/files/74933693823.pdfIn PDF document text
    • 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_off0000d539.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD539 18272 bytes
SHA-256: 919a28ef353b1e698e17db8242582882336b6e6e7f3e27f2d8c3812826c9af7e
font_01_sfnt_off00010544.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10544 10748 bytes
SHA-256: 14e72feb3287e7c5617117d1ec2b442f22bb2375a86ac55f476d649c326d1987
font_02_sfnt_off00011dde.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DDE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1