Malicious PDF — malware analysis report

Static analysis result for SHA-256 99de59839d09aef6…

MALICIOUS

PDF

67.6 KB Created: 2021-06-23 02:31:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-27
MD5: b65a2363d439b85fd78f4351098e0e13 SHA-1: d0499b0dc2461c2dde6ed61e412a72a0227a9f95 SHA-256: 99de59839d09aef6c28b56909ba10822c999317b5d492b14468e8ca67ca4e3f3
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The sample contains a link farm pointing to compromised WordPress upload directories, suggesting it is used to host or redirect to malicious content. The presence of numerous unknown URLs indicates a broad distribution or redirection infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/1608a8b16ea8e3---36300819672.pdf In PDF document text
    • https://asthasupermarket.com/userfiles/file/71222490925.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608abf2be59dc---50208732571.pdfIn PDF document text
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606e4b87c279d---sojunuzutivezot.pdfIn PDF document text
    • https://www.ideaklinik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160724afbd9983---31331029756.pdfIn PDF document text
    • https://fcksa.com/ckfinder/userfiles/files/tezabepi.pdfIn PDF document text
    • https://senzedigicraft.com/wp-content/plugins/super-forms/uploads/php/files/e0958d5829266a82dc1f574294d353d5/76071019378.pdfIn PDF document text
    • http://shinies.ru/img/lib/file/26001045743.pdfIn PDF document text
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/57c182e0f5cf73dc49da4c9283ab876c/22259860675.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16092bd564fea7---liwuzon.pdfIn PDF document text
    • https://www.azulejositurry.com/wp-content/plugins/super-forms/uploads/php/files/brpchul9c57sps2p08be6jn5r3/jobavidixereb.pdfIn PDF document text
    • http://2478.ru/admin/ckfinder/userfiles/files/labonuvowetekizadeluduz.pdfIn PDF document text
    • https://iescolumbus.org/wp-content/plugins/super-forms/uploads/php/files/e156aa3f9b80752b9e19f971253b5d34/27689629644.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/~3/1KS0DP0cxss/uplcv?utm_term=adobe+imageready+7.0+tutorial+pdfPDF 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cb1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB1C 5668 bytes
SHA-256: d5d6e0be0a3b65ac81715dd36d86aa86d579dc90a4e989c28fecbd69ea77a4ce
font_01_sfnt_off0000de63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE63 10356 bytes
SHA-256: 058f339b20f8e91538d7a942356b9a2d6bce92151f96b8aaad0420fffce92cfd

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