Malicious PDF — malware analysis report

Static analysis result for SHA-256 68a789c887882108…

MALICIOUS

PDF

73.5 KB Created: 2021-09-11 22:47:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: ab5d50654c7c5004ebdf02c10b1b65d3 SHA-1: 3b889e724148211eb90fd95849714b3f627a750f SHA-256: 68a789c887882108ffde59b1f0e767dbd1750e21dbb2714716cb9e0850549d82
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple compromised WordPress sites, specifically leveraging the 'super-forms' plugin for file uploads. The ML classifier strongly indicates maliciousness, and the structure suggests an attempt to lure users to external, potentially malicious, content. No scripts were extracted, but the PDF structure itself is indicative of a phishing or redirection attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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 https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/b3u16r9l8loiom6i51e47vageq/37558130380.pdf In PDF document text
    • http://www.guus.edu.mn/ckfinder/userfiles/files/wutoneb.pdfIn PDF document text
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/8857e64cd229efae6c273e8377f88378/fodowo.pdfIn PDF document text
    • http://bukhatirhomes.com/userfiles/file/givixadeninamibedu.pdfIn PDF document text
    • http://denki-shonan.com/uploadsfile/femejexa.pdfIn PDF document text
    • http://imoroz.by/upload/file/tetegoxofa.pdfIn PDF document text
    • https://biholka.cz/uploades/userfiles/file/nulanebofo.pdfIn PDF document text
    • https://yumasri.com/assets/ckfinder/userfiles/files/riwiremonemazuligopifemor.pdfIn PDF document text
    • http://lecieldesandes.fr/ckfinder/userfiles/files/3432773546.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/11e7abd26d2172ed860e5f9aa55437bc/kedelepotisi.pdfIn PDF document text
    • https://fundreamz.com/ckfinder/userfiles/files/wogimajibajetivofa.pdfIn PDF document text
    • http://wsm.hk/images/uploadfiles/file/wabasiluzilotebufeses.pdfIn PDF document text
    • http://pphu-joanna.pl/fckpliki/file/zejokovenekokagesudopo.pdfIn PDF document text
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161303a82b26ae---gigupepuwozo.pdfIn PDF document text
    • http://revucue.com/ckfinder/userfiles/files/sebijalovadun.pdfIn PDF document text
    • http://abaj.cz/UserFiles/File/sisimisotigixadop.pdfIn PDF document text
    • http://cosmeticdermatologymiamibeach.com/uploads/data/files/99526456810.pdfIn PDF document text
    • http://dorp.pl/userfiles/files/wifafalosazidofijam.pdfIn PDF document text
    • http://35ju.21tg.cn/uploadfile/ckeditor/files/97309822258.pdfIn PDF document text
    • http://uptownherndon.com/uploads/files/30107561124.pdfIn PDF document text
    • http://saharun.org/uploads/ckfinder/userfiles/files/sirimubipomuvofixomipefe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=how+do+i+cast+to+my+tv+from+my+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_off0000be2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE2C 10716 bytes
SHA-256: 0be7fa00728c2b8e17f95ea9e1965e8bbf5a038534523971f42c88b6d1ff9fde
font_01_sfnt_off0000d6cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000eedf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEDF 16308 bytes
SHA-256: b83a9a056cc56500158f997ef54eed7d662b4d1bf2fd422cf598884646c828cd