Malicious PDF — malware analysis report

Static analysis result for SHA-256 51ab3df688a03dc0…

MALICIOUS

PDF

77.4 KB Created: 2021-06-18 12:16:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 9d107b7000734af5bbc8eb5625cbdeb2 SHA-1: 3d77169858aef9ee111f0d89c9818d019fada21d SHA-256: 51ab3df688a03dc0cb4386381c362dfb58e151d23ab000432c4104fdea6dba27
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was identified as malicious by a machine learning classifier and ClamAV. It functions as a link farm, containing numerous URLs pointing to potentially compromised websites or disposable hosting. The document body is heavily obfuscated and contains metadata suggesting it was generated by wkhtmltopdf, but no clear user-facing content is discernible. The primary attack pattern involves directing users to external malicious links, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://keralahappyjourney.com/ckfinder/userfiles/files/rupofojodizedopanujuf.pdf In PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/hli2lae6e6cro7hmt14duislf0/xuludopidorafiwelilubuv.pdfIn PDF document text
    • https://perleyparish.org/wp-content/plugins/super-forms/uploads/php/files/e64370ae3814b6cedecf885f26e4f2a5/tisusupakegotixiw.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/b48e1444a5577d7e5c05096d613d7bc8/46812151880.pdfIn PDF document text
    • https://mrmobilewebsite.agency/wp-content/plugins/super-forms/uploads/php/files/d20ad01513f47b04479036643125c321/xufezivitutawijutagat.pdfIn PDF document text
    • http://www.empresasdelimpeza.info/wp-content/plugins/formcraft/file-upload/server/content/files/160c575578752c---83471498004.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5834cba656---77219492239.pdfIn PDF document text
    • https://www.hamburgeriaagricola.com/wp-content/plugins/super-forms/uploads/php/files/2imkpd1arep9bg2n0o58qalsh4/rakiwilatibadamoderorizo.pdfIn PDF document text
    • http://dailyxedayhang.com/userfiles/files/1300469510.pdfIn PDF document text
    • http://waukeganeast1980.com/clients/877304/File/47427629590.pdfIn PDF document text
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/1608b456ee0cc4---29564444177.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608761962d013---toresitido.pdfIn PDF document text
    • http://waelfawzy.com/userfiles/file/26818571868.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3593340db6---47272094545.pdfIn PDF document text
    • http://el-master.ru/userfiles/file/zepigimabed.pdfIn PDF document text
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/c46723a2cc6a86f7bbb79143189a71fd/vawolabivirokir.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/160b4b86cc53de---17121410389.pdfIn PDF document text
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/2ec59b5781911302a88dc2f47e499511/26976519523.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=marvel+future+fight+mod+apk+latest+versionPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e2d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2D0 3088 bytes
SHA-256: f5a6010e5f9fc00a912fa25add5ccb25ebe8c4245224df969a22ae60d01903bb
font_01_sfnt_off0000edd6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDD6 5584 bytes
SHA-256: 2c7cb858069bf9b3e9738d9579618fc9f0e8f67543dbc899aa19a08a56910135
font_02_sfnt_off000100c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100C1 11552 bytes
SHA-256: a3247768525c3174469302643342174c46ea16b30688055d00db90d8bea13694