Malicious PDF — malware analysis report

Static analysis result for SHA-256 472a3517ebc39a3a…

MALICIOUS

PDF

96.0 KB Created: 2021-09-17 21:07:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 15bb28ce737a081b9d006668643c26d7 SHA-1: 35cb0db55369d8d1007b5e7a054a0c5bb0efd227 SHA-256: 472a3517ebc39a3a481b63f907c7412f5be130bccb3d9b3393d1cf861b3cc59d
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a large number of embedded URLs, many of which point to disposable hosting or compromised CMS upload directories. The ML classifier strongly indicated maliciousness, and the structure suggests a link farm designed for SEO manipulation or to distribute further malicious content. No scripts were extracted, but the overall pattern of hosting numerous links is suspicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 5

  • 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 http://studiomistretta.com/userfiles/files/gifas.pdf In PDF document text
    • https://www.tahitotfalu.hu/ckfinder/userfiles/files/55405315659.pdfIn PDF document text
    • https://mabuksusu.com/contents/files/41800766665.pdfIn PDF document text
    • http://saothienemb.com/uploads/images/files/narozerutobafixikusopuwag.pdfIn PDF document text
    • http://epmachine.ru/d/files/90586013281.pdfIn PDF document text
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/f6735ad2affc1414bc053c22aaca245d/zazeronepuzex.pdfIn PDF document text
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/16141627f2d56c---38939310183.pdfIn PDF document text
    • http://dmkert.hu/files/file/97254074940.pdfIn PDF document text
    • http://cf2sc.cn/userfiles/file/32231577256.pdfIn PDF document text
    • https://arch.ua/ckfinder/userfiles/files/xexegerajevi.pdfIn PDF document text
    • http://drironcat.com/images/file/kexawuzetoxe.pdfIn PDF document text
    • http://99hospitalitygroup.com/ckfinder/userfiles/files/27189971628.pdfIn PDF document text
    • http://nujhimachal.in/img/uploads/files/41775487275.pdfIn PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/v1tmbja0tc2li0it9mp9tnqf7b/kagideroz.pdfIn PDF document text
    • http://silverk.ru/img/lib/file/61538122671.pdfIn PDF document text
    • https://albizy.com/ckfinder/userfiles/files/wudozo.pdfIn PDF document text
    • http://www.chubsorn.com/file/files/bojawiraxagubefukir.pdfIn PDF document text
    • http://jamones-luna.shopcloud.es/ckfinder/userfiles/files/86869755670.pdfIn PDF document text
    • http://alotercuman.com/ckfinder/userfiles/files/xakobatavotogalisonom.pdfIn PDF document text
    • https://capitalsyndic.com/userfiles/file/wijerobufew.pdfIn PDF document text
    • http://www.ecvbrass.ch/user/web/file/siduzuzubemupig.pdfIn PDF document text
    • http://dexgerm.com/data/file/userfiles/files/muvubemunegukazeke.pdfIn PDF document text
    • http://autoscuolecasetta.it/userfiles/files/51647106653.pdfIn PDF document text
    • http://wdnederland.nl/file/89724595945.pdfIn PDF document text
    • http://trongtinpc.com/luutru/files/67882959187.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=auto+followers+instagram+unlimited+freePDF 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_off00011123.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11123 10864 bytes
SHA-256: 9a764dea44c8bd0ba4f7814c016a3ad095753660b1d181886f670df634ee3789
font_01_sfnt_off00012a1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A1B 18416 bytes
SHA-256: a3883b0ef447baf1abb944d785cabb542ce616132bcf320ba7a0c948a5effcd3
font_02_sfnt_off000159fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x159FD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1