Malicious PDF — malware analysis report

Static analysis result for SHA-256 537b99a08c4c2a07…

MALICIOUS

PDF

103.4 KB Created: 2021-07-18 21:55:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 87234d08886830d2fce3417eb4f597c0 SHA-1: 20e39294eb7789d1cfe4e34b57574ca57857dc4f SHA-256: 537b99a08c4c2a07e01258dd4f12f567f865e8ade6010da6644a8403872cbf95
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains embedded JavaScript and numerous links pointing to compromised WordPress upload storage and other disposable hosting sites. These links are likely used to redirect the user to malicious content or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9926

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://gowowdeli.com/uploads/files/zerifapesorubetagoda.pdf In PDF document text
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/63c9a891671b5b80a86d21fbabae207b/rabizoputumofiwosemimov.pdfIn PDF document text
    • http://au-coeur-du-temps.com/userfiles/file/91078895284.pdfIn PDF document text
    • http://shiinamotors.com/js/upload/files/bujobowaxeponipuroban.pdfIn PDF document text
    • http://villaturri.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608bd5e19b7aa---22321373230.pdfIn PDF document text
    • https://xn--faades-mtal-n9a6a.ch/ckfinder/userfiles/files/womerulebi.pdfIn PDF document text
    • http://reikihaus.com/clients/75291/File/84691727758.pdfIn PDF document text
    • https://oxi-dental.ro/imagini_ws/28527493224.pdfIn PDF document text
    • https://nazragame.com/calisma2/files/uploads/44960541911.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072a4b0be22e---jasudepujo.pdfIn PDF document text
    • https://sf-tfi-pgu.uz/wp-content/plugins/super-forms/uploads/php/files/254d00ac6a9b8885f3b0a377c0fcf32f/xunalifi.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/167544af4b9cbe6a5f02ba7ff07f077e/bunubarapanuwesofora.pdfIn PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/ae7a0f1729a94675268fe5e901700029/1066240190.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/9e71e641813f6b83c60d6826070c474d/4542504385.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160802e91a49c0---30336044646.pdfIn PDF document text
    • http://makaeximworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076cf2911778---jukuverijepaluz.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16076500394efd---voboxoberumozi.pdfIn PDF document text
    • http://alteredcompta.com/buddha/ckfinder/userfiles/files/fawapurekigomituzajomav.pdfIn PDF document text
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/160952b5d8074e---94565993621.pdfIn PDF document text
    • https://faresaldabbous.com/uploads/files/92105850341.pdfIn PDF document text
    • https://sarujiovalente.com/wp-content/plugins/super-forms/uploads/php/files/hd3nf4v7rj13clf90iht60pm28/57579164268.pdfIn PDF document text
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c53670c6313---31453694441.pdfIn PDF document text
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/7as7d1dlalec3srss3dovqmtl5/64927449860.pdfIn PDF document text
    • https://hijaulumut.com/contents//files/fuwedijuvoko.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=all+ant+and+decPDF 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_off00013405.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13405 17292 bytes
SHA-256: 6a2a17746c711fdcef56cff78d520b86bca668ca11b1d9bec301aa0f45666447
font_01_sfnt_off0001612e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1612E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00017944.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17944 9864 bytes
SHA-256: 0b1d7884a5529544339880cafc11c98f9b85bd7bc9614a4f70305a205dd8d71d