Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3ca498168de7c9b…

MALICIOUS

PDF

80.5 KB Created: 2021-09-21 13:52:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 37fe79a51db55e0094a0192c9be8841a SHA-1: acbfa9b04648503e7f23afcd3ebab26aa32ad1bb SHA-256: a3ca498168de7c9b98cd41fb081e5f6c0a7b8c609aec124551aed5ac11f0c12b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was detected by ClamAV as Pdf.Phishing.Trojan and an ML classifier with high confidence. It contains numerous links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The presence of these links indicates an attempt to lead users to malicious sites, likely for phishing or to download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://woykoff.hu/upload/file/gupuzowobapo.pdf In PDF document text
    • https://hotelite.in/userfiles/file/75888094303.pdfIn PDF document text
    • http://mdsalon.ru/img/lib/file/68629831996.pdfIn PDF document text
    • http://cualuoiskydoor.com/webroot/img/files/xavalurig.pdfIn PDF document text
    • https://brianhigbielaw.com/UserFiles/file/turetigipejifurizaje.pdfIn PDF document text
    • http://aadcnfgl.netsociality.com/upload/files/dozinewijirut.pdfIn PDF document text
    • https://embassyinvietnam.com/webroot/img/files/pogiwebanazesaw.pdfIn PDF document text
    • http://tongkhomica.com/upload/files/57111558020.pdfIn PDF document text
    • http://cl-pub.com/files/files/3911259749.pdfIn PDF document text
    • http://movitecnic.com/ressource/site-image/files/sowujenujubevegero.pdfIn PDF document text
    • https://dollarplus98.com/images/upload/files/fazepot.pdfIn PDF document text
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613318eb81bfc---94873738435.pdfIn PDF document text
    • http://snabsz.ru/ckfinder/userfiles/files/55119987906.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/c8f15bd282cf9d369ace9ac775dac3c0/14046245042.pdfIn PDF document text
    • http://alrabbancapital.com/file/files/zitilesogalubuwutof.pdfIn PDF document text
    • http://krevue.cz/UserFiles/File/fojoxejadaboxe.pdfIn PDF document text
    • http://sochisushi.nl/survey/userfiles/files/71209420840.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/60153703044.pdfIn PDF document text
    • http://chinastom.ru/userfiles/file/forir.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613a48e52f151---lebimutinuku.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139e8a774428---midado.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=how+to+record+system+audio+in+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_off0000d75b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD75B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF72 10776 bytes
SHA-256: 822581632c240e618917c1d52fa306dff5c2747fe7e61c22c8a26c9427de7018
font_02_sfnt_off0001084c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1084C 16892 bytes
SHA-256: bf2368b28360c44898761f4b8934780a542a1bddd3fc4637ae22de5f48a447ec