Malicious PDF — malware analysis report

Static analysis result for SHA-256 21b81447c25eee8e…

MALICIOUS

PDF

80.9 KB Created: 2021-06-13 11:42:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 0d3ba6de18e82e2d31527cdeb25dabc4 SHA-1: 1bf09588b4ae6f87edf48954393d414968032bfc SHA-256: 21b81447c25eee8ea92f107ee3c201518b9e4b41c8babc783a132ac014e0db72
184 Risk Score

Malware Insights

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

The PDF document contains multiple heuristics indicating it is designed to trick users into downloading files, including links to compromised CMS uploads and disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of a 'download button' heuristic further supports the lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://ketchas.ru/uplcv?utm_term=watch+dogs+download+for+pc+highly+compressed PDF link annotation
    • https://ajitcoatings.com/uploads/52997571758.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/1astqhp1045oe3vceb51827alk/99078900479.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/nlq1st5vn76l9e8qg6g2rna8q1/gidumireribulalal.pdfIn PDF document text
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16078768480747---tinivozabumed.pdfIn PDF document text
    • http://unesco-mediain.cz/fckfiles/file/bafivolozubivekenid.pdfIn PDF document text
    • http://wingprocess.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/bivok.pdfIn PDF document text
    • http://stylowa-pss.pl/userfiles/file/tunefotaw.pdfIn PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081724f0d9bb---vikuzugujadin.pdfIn PDF document text
    • http://kirakuramenandsushi.com/uploads/files/kajefaxunujurejeledil.pdfIn PDF document text
    • https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/e76261c0bea0def1cbeef29fd39fe662/23203968184.pdfIn PDF document text
    • http://rsst77.ru/upload/files/konajukupitonomu.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c23734687e0---43574318515.pdfIn PDF document text
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/4noler6203hdp26vdqninjdita/nesifaluwiwij.pdfIn PDF document text
    • http://hainescentreasia.com/images/file/ralikinunowurijubu.pdfIn PDF document text
    • http://79.170.40.182/boothtastic.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a147d5182c0---83229448019.pdfPDF link annotation
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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_off0000fe90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE90 5776 bytes
SHA-256: 42b602d7de0d86260057c4f82f54b9ab86507f2116c3aebac45f7174c90607e0
font_01_sfnt_off0001123a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1123A 10628 bytes
SHA-256: 8bbf64e194f9193a210221b2be0ce0e4a9637fdf7fb38064856dcbbe393bef65