Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef736598e615d990…

MALICIOUS

PDF

75.0 KB Created: 2021-06-09 12:03:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: d3540ec81ebb2a7651bd66bef3fc4421 SHA-1: 29564c7ac4c047be44f8aedf11925eb3afe488be SHA-256: ef736598e615d99014ad41b9e246880f3befbc4d1f982ff7ea7039bd176cf8fc
156 Risk Score

Malware Insights

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

The PDF document contains numerous links to external websites, many of which are hosted on compromised WordPress sites. The document body, though heavily obfuscated, suggests a lure related to 'scale factor finding sides worksheet answer key'. The presence of multiple PDF link farm heuristics and a high ML classifier score indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted from this sample.

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 https://cructi.ru/uplcv?utm_term=scale+factor+finding+sides+worksheet+answer+key PDF link annotation
    • https://www.unicodesystems.com/wp-content/plugins/super-forms/uploads/php/files/2s8onj9fla4hums57e8cd52485/1911873815.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160822b5fbd097---suxujolokumuxasaduzorev.pdfIn PDF document text
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/lpcj2v1r2l45p7inqkoimdqqv0/94224634525.pdfIn PDF document text
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/8a71b038f6bddae69a6a6050d7eb1643/18063555239.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609a4bf549071---81470348096.pdfIn PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/btt8se0ljmt1vlgr7bmj3spl1g/34638594975.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/33bb4cf4664b51ceb7843005918f4386/50305257121.pdfIn PDF document text
    • http://work4shop.cz/userfiles/file/12457861939.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609621d7172c1---11878536249.pdfIn PDF document text
    • http://alkanboya.com/files/file/%5C/70809802705.pdfIn PDF document text
    • https://nhathuydesign.com/wp-content/plugins/super-forms/uploads/php/files/igftom3us3tm6om1cff2447a8d/boditeguwuwoj.pdfIn PDF document text
    • http://amako-ra.com/wp-content/plugins/super-forms/uploads/php/files/9b9cd97297e69a58ab0f6facc9b0284f/zadejuruvebirapu.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b054c4c924---salojogetowagejegufo.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a62f339068a---50242406185.pdfIn PDF document text
    • https://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/3gsteekmrrlspqda7cf7g3nj5g/manul.pdfIn PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/cd8d0659d0f61985aa4dea8082f75d91/wavugurupusezonodurek.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ef1d42b40e---94358657107.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_off0000e727.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE727 5644 bytes
SHA-256: f8d1a7b631a569821159746d98b5b74a7b75536176f6b4a0a71bdd54a81671c3
font_01_sfnt_off0000fa6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA6D 10632 bytes
SHA-256: 6b07c069658f88bd8ec23bc16b206961fbae844384b26e06c97f08af7c765e7c