Malicious PDF — malware analysis report

Static analysis result for SHA-256 5dce7c81ef15d141…

MALICIOUS

PDF

81.5 KB Created: 2021-09-17 10:17:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 76b6a751d78fa02f7eb83e1b20f695ba SHA-1: d13a61cdb1738b4f8b216c9528feb59bd641bf3b SHA-256: 5dce7c81ef15d1418295d3742be52020741794b3a02c3439ffe2b4af8d3daf7f
116 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The PDF file contains a link farm pointing to multiple compromised WordPress upload directories, suggesting an attempt to distribute malicious content or redirect users to phishing sites. The ML classifier strongly indicated maliciousness, and the presence of numerous external links, some on disposable hosting, reinforces this assessment. No scripts were extracted, but the document's structure and URL targets indicate a lure for further compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 6

  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://on-call-anatomist.org/ckfinder/userfiles/files/48502696997.pdf In PDF document text
    • http://all-premium.com/user_file/files/911122232.pdfIn PDF document text
    • http://lnyuanzong.com/uploads/files/20210901051426.pdfIn PDF document text
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/161364d94d0614---8460850777.pdfIn PDF document text
    • http://sunpix.ru/img/lib/file/fuvibegezivevutamagenevuz.pdfIn PDF document text
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/4c045477592d4d2d8a9f428e97649592/52373072265.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613df1515b853---19082994886.pdfIn PDF document text
    • http://zjqzzx.com/uploadfile/file/2021090621482073499.pdfIn PDF document text
    • http://bkm-market.net/userfiles/file/fokiboxo.pdfIn PDF document text
    • https://taucaotoccatba.vn/images/news/files/ziwekimov.pdfIn PDF document text
    • http://studio-orlandini.com/userfiles/files/96217463056.pdfIn PDF document text
    • https://galerieportelouise.be/userfiles/files/xixuze.pdfIn PDF document text
    • http://www.biosafety.biz/ckfinder/userfiles/files/34436356291.pdfIn PDF document text
    • http://japhina.com/upload/file/5699752510.pdfIn PDF document text
    • https://badeluxe.com/userfiles/files/74051322966.pdfIn PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/b58ae2f28cd8827aa3f710b026cd1a7a/91789117798.pdfIn PDF document text
    • http://cdkuys.handysociality.com/upload/files/53699631539.pdfIn PDF document text
    • https://pharma-tools.pl/galeria/file/83012993423.pdfIn PDF document text
    • http://mos-craciun-inchiriere.ro/fckfiles/file/7310268371.pdfIn PDF document text
    • http://www.pavimentosyreformasferlu.es/ckfinder/userfiles/files/98195408296.pdfIn PDF document text
    • https://treasurehunterdetectors.com/ckfinder/userfiles/files/muful.pdfIn PDF document text
    • https://www.uflo.edu.ar/ckfinder/archivos/documentos/gaxibos.pdfIn PDF document text
    • http://ingatlanfelugyelet.hu/uploads/file/86017461489.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/16133057555233---91980448627.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=bloquer+pub+dans+application+androidPDF 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_off0000d59b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD59B 10948 bytes
SHA-256: 0d28f2114c2c10e3d5aad9da0ca82895513ae5012ff3888a4a7282671781c144
font_01_sfnt_off0000eea1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEA1 18512 bytes
SHA-256: 14c8bdbd48bd605ed1f6690ffdba71c031134491a966cc24e21f5b797d7aeb4b
font_02_sfnt_off00011eed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1