Malicious PDF — malware analysis report

Static analysis result for SHA-256 aba77f8a27518752…

MALICIOUS

PDF

76.1 KB Created: 2021-07-06 16:47:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5cea76b61cf16e0a3039424db29b5d56 SHA-1: c1ed9ae2fd123aa4ec7ecd7459cb75547f5fab6f SHA-256: aba77f8a2751875269326359c836894176422461d17778924a0a9d7eda4fa2a7
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to compromised CMS upload directories, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://pk-kuepfer.ch/ckfinder/userfiles/files/83759140689.pdf
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c7325e2376---kanupiripepenupewebi.pdf
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/63200c19f77bd8bcd3f091f187f5e4f7/14995419962.pdf
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608845cb47c12---rogatigifoteranaw.pdf
    • http://stevis.cz/files/file/18184094414.pdf
    • http://thegreenlegacykeepers.com/clients/e/e8/e8dc17949b7ef813e9937e453902477f/File/48685495677.pdf
    • https://myparrotfood.com/user_files/files/55511760047.pdf
    • https://ltgtrends.com/wp-content/plugins/super-forms/uploads/php/files/d00593d2845b9370fa6b1db61d68f7f3/46252755272.pdf
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bbf3964a1a9---pivuxojem.pdf
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/d888dbbd1d48ea318a907c92036a24b1/41684451635.pdf
    • https://e-lightingcontrols.com/wp-content/plugins/super-forms/uploads/php/files/458abfacff34aefc14f93336624faa3e/8305553741.pdf
    • http://ekotronic.eu/files/file/65403972050.pdf
    • http://goteneplast.se/files/images/file/todepedufem.pdf
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608622ce7fbf7---jusegigupojogikopakewofe.pdf
    • https://ensasoft.com.tr/wp-content/plugins/super-forms/uploads/php/files/8modqf208267luq9mst92glker/jezagove.pdf
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/1e4c77cb49ba62996bca765398ae6111/89938439437.pdf
    • http://staractivecollection.com/resimler/site/files/feramabexipikezufut.pdf
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087fbc54b40b---miguvilekakotax.pdf
    • https://nolimitscenter.be/peausitive/images/FCKeditor/file/42004945829.pdf
    • https://motelandratecuci.ro/userfiles/file/letes.pdf
    • http://english-life.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160792f32a43e7---29511376593.pdf
    • https://canadianrelocation.net/wp-content/plugins/formcraft/file-upload/server/content/files/160cd2aa43e4d3---28863053544.pdf
    • http://xn--clinicaquirogavilario-vbc.com/wp-content/plugins/super-forms/uploads/php/files/vd24tg46lrvvfpnb9vclcsbeq7/52603435211.pdf
    • http://xn--80aaeiengkwpz6p.xn--p1ai/pub/file/kazodebowelapegezaro.pdf
    • http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/11cb4ee2f5240febde25509f9224fefc/97774595270.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=the+survivor+rusty+forest
    • 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_off0000ca20.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCA20 16792 bytes
font_01_sfnt_off0000e237.bin
2fa7a727caddd59da5678c06550a4057358573065f19e09638f3ecd2b4d3e9a5
pdf-font-stream PDF embedded font (sfnt) at offset 0xE237 10244 bytes
font_02_sfnt_off0000f96e.bin
e5ba64bae4fa012aeb71c77740666cbf456d14d03376e427360a9f43458ad933
pdf-font-stream PDF embedded font (sfnt) at offset 0xF96E 16096 bytes