Malicious PDF — malware analysis report

Static analysis result for SHA-256 7a535c663cb86023…

MALICIOUS

PDF

90.9 KB Created: 2021-08-04 09:42:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 28567ea8c2d6ee7de04000d94f34fa0c SHA-1: 23d934019fa06ccfdcb83c8e2df463595236d5c5 SHA-256: 7a535c663cb860233041e8b7f6d0084d09f0e6aa5ffaa345a42447613daa18f5
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress sites and other disposable hosting, suggesting a link farm used for phishing or malware distribution. The PDF structure itself does not contain readable content, but the presence of these external links is the primary indicator of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9765

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://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/16098c40be58dc---17156386519.pdf In PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/80b6snpm7ln0at43g59ip6lqna/66300033373.pdfIn PDF document text
    • http://pickup-ws.com/userfiles/files/tebivafonorodufek.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160e3251124693---59843332636.pdfIn PDF document text
    • http://biancoacolori.it/userfiles/files/kunenofejavewimax.pdfIn PDF document text
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16090ffae6374e---fufolikubuger.pdfIn PDF document text
    • http://painttechvina.com/webroot/img/files/13063534044.pdfIn PDF document text
    • https://ascinfratech.com/clientprojects/trading/file/vinatasobubonod.pdfIn PDF document text
    • http://www.makattakasinti.com/wp-content/plugins/formcraft/file-upload/server/content/files/160704e398e8df---texapelav.pdfIn PDF document text
    • http://inwallendorf.de/userfiles/file/71990181208.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/92003921589.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bf121a0f8ce---92334822803.pdfIn PDF document text
    • http://elyriahigh1974.org/clients/0/05/052ab20d644b737728595af1a47b4450/File/didajofune.pdfIn PDF document text
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/f418e6c0e4109d594e1f5a478a5055c3/fekosupilagaloxuvo.pdfIn PDF document text
    • http://www.kickcommerce.com/userfiles/file/68222785397.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d3f9d93753f---13427994052.pdfIn PDF document text
    • https://banderlogclub.ru/Files/file/petobozavuja.pdfIn PDF document text
    • http://opalsolar.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16091718c8f78e---73918376637.pdfIn PDF document text
    • https://www.lashharmony.co.uk/wp-content/plugins/super-forms/uploads/php/files/2qkn17ds40160r526l473lf7a9/fodemixim.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608828d1d9e01---60310608382.pdfIn PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608cefa7938a4---robenovis.pdfIn PDF document text
    • https://caravanandre.it/wp-content/plugins/super-forms/uploads/php/files/a85b50030601103b6e4cbb4aa8fee033/40007273837.pdfIn PDF document text
    • http://brandweeramsterdamamstellanden.nl/userfiles/file/xadowapepiwo.pdfIn PDF document text
    • https://protradingindia.net/userfiles/file/37838490053.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/87f0659a759ce853ebf3a5cb0543eb54/42532556662.pdfIn PDF document text
    • https://gagiongvitgiong.com/ckfinder/userfiles/files/wumunopupemedakabusodive.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=who+can+attest+as+gazetted+officerPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e803.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE803 16252 bytes
SHA-256: bfc7ce51a1a9b37382af61f0075eb0cdb972126da031002d338643432d80e6e4
font_01_sfnt_off0000fddf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDDF 17364 bytes
SHA-256: 9d370d84527819457fbcfd84deb324e236f43a95355d980ce11ea85d93ef6dff
font_02_sfnt_off00012b3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B3A 10760 bytes
SHA-256: 9480dca9d9d8707aef36457b1404e5f0e741e8ade9acabb444ee707c57528a6a
font_03_sfnt_off000143d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x143D2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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