Malicious PDF — malware analysis report

Static analysis result for SHA-256 a153cbffdfa0cbb7…

MALICIOUS

PDF

75.2 KB Created: 2021-06-09 09:59:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 5d352a44767fb167e46b08edee816401 SHA-1: 8c3c10803b865dce883e858d41481bedf57f69fd SHA-256: a153cbffdfa0cbb798b0b5cc59580cd5c99b6cdd114a87f4ccfd60966126a295
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is a PDF document that contains numerous external links, many of which point to compromised websites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest it acts as a lure to external malicious content.

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://pixomot.ru/uplcv?utm_term=free+music+theory+worksheets+pdf PDF link annotation
    • http://alnoorcity.com/userfiles/file/sepemenapovoxegabiges.pdfIn PDF document text
    • http://veraschwemmle.de/fckdata/file/dosove.pdfIn PDF document text
    • http://cropscipublisher.com/files/upfiles/file/wenofitimaromujajijosupu.pdfIn PDF document text
    • http://www.empresasdelimpeza.info/wp-content/plugins/formcraft/file-upload/server/content/files/160926cfd7cb6e---sololanasirigepamuvo.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608015c98e8b5---dumewilidiwowifokuwike.pdfIn PDF document text
    • http://orvosvalaszto.hu/uploads/files/79430308648.pdfIn PDF document text
    • http://www.zopfitravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c8b8992aa7---matupujuto.pdfIn PDF document text
    • http://futurepoolandspa.com/ckfinder/userfiles/files/25491857892.pdfIn PDF document text
    • https://www.dynasil.com/wp-content/plugins/super-forms/uploads/php/files/9a2699d5992c96108c455994dfff99d3/pefizuveropazobesikef.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160afa81b03374---8873169526.pdfIn PDF document text
    • http://aps-mes.com/files/file/41289929899.pdfIn PDF document text
    • https://noddy.nu/images/file/munalovaragi.pdfIn PDF document text
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/c2p3ot6esgvud0e394d90e1nlm/57200738016.pdfIn PDF document text
    • http://letsbelegal.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/38719169514.pdfIn PDF document text
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160aad36cac638---rafilekivatageruworow.pdfIn PDF document text
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16093b236b57b1---60461799975.pdfIn PDF document text
    • 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_off0000e77c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE77C 5364 bytes
SHA-256: bfc699f61ba78648f00939bd58205fddbb054afdc5fadb862c0fd0c54a20fe4f
font_01_sfnt_off0000f9b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9B4 11156 bytes
SHA-256: e9a0800595d4fbaf8cec39051a3f494777172cac42dfc007e11b32ec7ae799d6