Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d3719f6850c3fe6…

MALICIOUS

PDF

70.2 KB Created: 2021-06-25 10:03:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: d4d7ee86673246c535975e2586d31628 SHA-1: b4e32dd6dc886ce79d5f6e588dd474966f8b9783 SHA-256: 4d3719f6850c3fe6c875f2fbdcadbfa66e40fce853d344219bf2593e5121c762
204 Risk Score

Malware Insights

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

The sample is a PDF containing embedded JavaScript, which is a common technique for delivering malicious content. It includes numerous links to external URLs, many hosted on compromised CMS platforms, suggesting an attempt to distribute further payloads or conduct phishing. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/6d125e519f76d9eb7845e484325cd877/16231461112.pdf In PDF document text
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/pdohe3mq5vcde1cgsegs2vb5s6/34616941332.pdfIn PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/465ae1937851fc20f64ba99e5b126f48/33244982646.pdfIn PDF document text
    • http://nensi.si/upload/file/vazufa.pdfIn PDF document text
    • https://erinmillssmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/geaegob6n97779n0qtn72pqjk0/82731331992.pdfIn PDF document text
    • https://daluxerealty.com/wp-content/plugins/super-forms/uploads/php/files/ej3hvb1f9luftb4s4jd14nnje3/junazavokokere.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/a165d34ce1866e83a1fa0dc00e2366f6/14499740835.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607055dccb8b1---52098702245.pdfIn PDF document text
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/660etsmibl4pifkkggi8ii2886/26729665210.pdfIn PDF document text
    • http://sage-chem.com/image/files/20210621_120911.pdfIn PDF document text
    • http://gunjanjain.com/app/webroot/js/uploads/files/bigivarofaxagexajakaku.pdfIn PDF document text
    • http://dashoernerboot.de/userfiles/50206920296.pdfIn PDF document text
    • https://ancoraeducacion.com/images/23343196312.pdfIn PDF document text
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609e5826781bf---tevab.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/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=scrum+master+roles+and+responsibilities+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_off0000d47c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD47C 5544 bytes
SHA-256: be7944c3b40ed9961f91269e7891f5f65ac5c778e0e29e668f3469ad017a073f
font_01_sfnt_off0000e730.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE730 10744 bytes
SHA-256: bccc2b056011e0972374ae1469cf5c20249411014ff8c56359fa90ca667a3eac