Malicious PDF — malware analysis report

Static analysis result for SHA-256 c535564cb02d1f26…

MALICIOUS

PDF

72.9 KB Created: 2021-09-03 05:04:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 3ba998f0937ddd950e1e370d8f3440aa SHA-1: 746483d12781fea7501de1966af28345a1b9165a SHA-256: c535564cb02d1f2615cbaac1508efc36d31a376088caadd67ab0026a9faa480c
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to various websites, including those on compromised CMS uploads. This suggests the document is designed to lure users to malicious sites, likely for phishing or to download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://centrorevisionimonregalese.it/file/soxolebuwuxe.pdf In PDF document text
    • http://tykhestudiodesigns.com/clients/7/73/7311521ca682816632878891c231d107/File/ninunu.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/7abd530c582d86db00e432cab3787388/28418490046.pdfIn PDF document text
    • https://flyags.com/editorResources/file///49450468232.pdfIn PDF document text
    • https://defi128.com/userfiles/files/mesugukum.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/41340969690.pdfIn PDF document text
    • https://agrimal.pl/userfiles/file/47680053294.pdfIn PDF document text
    • http://kursadowicz.pl/Upload/file/jivododipusetaju.pdfIn PDF document text
    • http://digitalpolicycouncil.com/imagenes/file/wudixexozozeteromu.pdfIn PDF document text
    • http://cleanyachts.it/writable/public/userfiles/file/17933190589.pdfIn PDF document text
    • https://b2cexpressdemo.com/userfiles/file/38812174321.pdfIn PDF document text
    • https://francois-daulte.com/ckfinder/userfiles/files/venumibokoxulawinu.pdfIn PDF document text
    • https://investainternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098e5acc7d5c---bilimufaxoforeruwisuwazas.pdfIn PDF document text
    • http://kaies.cn/upfiles/file/vafositut.pdfIn PDF document text
    • http://studiosimonepantaleo.it/userfiles/files/56826606545.pdfIn PDF document text
    • http://bhhangkhong.com/upload/images/files/wulexofebusibedusuk.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/160dc242b909c2---rawirowisogi.pdfIn PDF document text
    • http://congtyvima.com/images/Download/52610046731.pdfIn PDF document text
    • https://himalayanwanderer.com/himalayan/userfiles/files/72818152455.pdfIn PDF document text
    • https://www.mii.net/wp-content/plugins/super-forms/uploads/php/files/2ac6fd856ebaa63676ceabfb2efffcf1/61046133216.pdfIn PDF document text
    • http://bygreenpure.com/userfiles/file/20036227287.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/80a35b75d5bbc5d6cd312ff39f188659/vawizavuwebizemoz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=monatomic+ion+naming+worksheetPDF 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_off0000bb04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB04 16648 bytes
SHA-256: fd3360c273d550d5c6ef70d789e05713326bf23ab60c3c55b26764ee4fc5efd2
font_01_sfnt_off0000e57d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE57D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fd94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD94 10800 bytes
SHA-256: 85fe6e07bc68f96fa6d03c7e4f2ef3d932b280805ed00dcb0475d225b8578caf