Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa7955eb5172af04…

MALICIOUS

PDF

80.4 KB Created: 2021-09-15 23:08:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: a3b201e5a47d9cde386d40c5d7d94027 SHA-1: bfb3157da68b9b55708124b989838640f54b317a SHA-256: aa7955eb5172af04e63f6a23abe2489c7ccdada1756888f53359cb3637f6e9a2
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple websites, some of which are hosted on compromised CMS platforms or disposable domains. The ML classifier strongly indicates maliciousness. The document body is heavily obfuscated and unreadable, suggesting an attempt to hide its true purpose, which is likely to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://tobn56.com/UpFiles/file/dejigisidetiberarukujev.pdf In PDF document text
    • http://yasairamenbar.com/uploads/files/xetarofonejit.pdfIn PDF document text
    • https://eqonetech.com/upload/userfiles/files/wevutugopemodu.pdfIn PDF document text
    • https://amatnieks.com/pictures/image/9098559136.pdfIn PDF document text
    • http://studioaba.net/userfiles/files/60900972267.pdfIn PDF document text
    • http://hemeringen.de/ckeditor_ablage/userfiles/files/85996615111.pdfIn PDF document text
    • http://vodnik48.ru/content/file/xovemogowajixebo.pdfIn PDF document text
    • http://phukientubepxinh.info/gomsu/sanpham/anh/files/gojedojewetemubumetoxofa.pdfIn PDF document text
    • http://kapfenberger-schuetzenverein.at/userfiles/file/lusataleke.pdfIn PDF document text
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/16136b43bd17e9---fogitunojonalajinerutamad.pdfIn PDF document text
    • http://huyminhplastic.com/upload/files/doluxuleleronowulik.pdfIn PDF document text
    • http://www.bongbansaigon.com/uploads/files/47841644279.pdfIn PDF document text
    • https://bwawarszawa.pl/upload/file/gigodod.pdfIn PDF document text
    • http://enjoyisagenix.com/ckfinder/userfiles/files/wixetejozofa.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613468b815021---62483101337.pdfIn PDF document text
    • http://sakurahoaanhdao.com/webroot/img/files/84772922812.pdfIn PDF document text
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/161400429e220e---futinupejokeli.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613148c0a1118---lovomixedaronologufob.pdfIn PDF document text
    • http://zagazzo.com/userfiles/file/25767213145.pdfIn PDF document text
    • http://ibtaker.ps/userfiles/file/dedadikotekadulowo.pdfIn PDF document text
    • https://bilbox.es/wp-content/plugins/super-forms/uploads/php/files/6dd3ba44e8e0055b9b5208f752a2465b/28842576514.pdfIn PDF document text
    • https://dcicz.org/userfiles/file/19845465961.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=soccer+physics+online+multiplayerPDF 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://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_off0000d99c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD99C 10928 bytes
SHA-256: bf302767a52d117ce167b917c2b923b00669b2c40c9d5b84e13c7c29e37aafb7
font_01_sfnt_off0000f2b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2B6 17756 bytes
SHA-256: f271dbddbcaad5128948d05cdb5091458e6f6fc2976e0cf18bd00788be869e53
font_02_sfnt_off000120ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120AD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1