Malicious PDF — malware analysis report

Static analysis result for SHA-256 8388aa068a36748e…

MALICIOUS

PDF

77.0 KB Created: 2021-06-09 13:07:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 57d272318a9f45c51a9582b964e00154 SHA-1: b96c52bf740f7c5ab999fc64a365bcaaee2beb17 SHA-256: 8388aa068a36748ecaf7b84ad255943c1c8d64956184cee741b7b1882488e7fa
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many hosted on compromised WordPress installations, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for distributing malware or phishing credentials. Although no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a malicious document designed to redirect users to potentially harmful 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://krisoc.ru/uplcv?utm_term=essay+book+review+example PDF link annotation
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160898eeb7abb5---segumav.pdfIn PDF document text
    • https://nanyangtextile.com/userfiles/file/bugilonixinur.pdfIn PDF document text
    • http://app8itebarandgrill.com/admin/images/file/87071864270.pdfIn PDF document text
    • http://kovacsoltvaskerites.hu/images/file/kenejuvolofilapilo.pdfIn PDF document text
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608583831cc1e---widosofepenajuzid.pdfIn PDF document text
    • http://www.ibadirect.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d096395990---5216082819.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160812782bdf22---sulikiwizetigisogelakemix.pdfIn PDF document text
    • https://grafitpoint.ru/wp-content/plugins/super-forms/uploads/php/files/0042948116eb48d57550a3d374f384ea/62353270671.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c9bed9e2d6---xuvufutufaworusuv.pdfIn PDF document text
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/2b6a49849e9c8dd287449070e9181ac6/xedagenosixebupizumetisi.pdfIn PDF document text
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/bd8561ebe837a1b592d06b9e47df9762/nufetizasesupugivolu.pdfIn PDF document text
    • http://technoculture.cz/admin/upload/file/64814013349.pdfIn PDF document text
    • https://ehblending.com/wp-content/plugins/super-forms/uploads/php/files/a2de02e8d906af2309ef7d897ea4da1a/27142790381.pdfIn PDF document text
    • http://bpabv.nl/uploadfiles/file/89598322320.pdfIn PDF document text
    • https://instalacje-elektryczne.net/ckfinder/userfiles/files/gokutuk.pdfIn PDF document text
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/cbkg11c147rr5oo24c4veg5qrk/52330258370.pdfIn PDF document text
    • https://southernlightingsource.com/wp-content/plugins/super-forms/uploads/php/files/7e8343d58d18c8e457fbcfe4c03441a1/solele.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_off0000f0b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0B3 5448 bytes
SHA-256: 3ddcc1c1d04a76ab596bbc6808476b4816ac9ef4bb0160a1fb8e23bcb8c3af29
font_01_sfnt_off00010346.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10346 10416 bytes
SHA-256: e1b977ab86c770451295bbeca1e253e190812abb67a1dd89787dc2a23ea2a356