Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3914a323c52e798…

MALICIOUS

PDF

85.7 KB Created: 2021-09-21 03:36:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 05b5d182440838d48f3bc4adc4363ab2 SHA-1: 75136a7bf93a35d1e0dc685fdc61cb9057254c6c SHA-256: b3914a323c52e79800470c30d14967f9f65f96d858662e372c275d38aa070d0f
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised or disposable hosting domains, suggesting a link farm or redirection scheme. The ML classifier strongly indicated maliciousness, and the presence of multiple PDF-specific heuristics related to URI and link farms supports this assessment. No scripts were extracted, but the primary attack pattern appears to be directing users to external, potentially malicious, resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://wastran.ru/uplcv?utm_term=principles+of+economics+2e+pdf PDF link annotation
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/1613985665f6dd---gerozawefu.pdfIn PDF document text
    • https://gbp.dropship-online.com/userfiles/files/67029953395.pdfIn PDF document text
    • https://avigailpekelman.com/sites/default/files/file/panedigepitu.pdfIn PDF document text
    • http://dlzhrjd.com/images/uploadfile/files/xitupadimijeme.pdfIn PDF document text
    • http://daejonggyoyc.com/userfiles/file/20210911085445.pdfIn PDF document text
    • http://thuaphatlailongthanh.vn/upload/contentFile/minhchau/file/51655748433.pdfIn PDF document text
    • http://yushendesign.com/images_fck/file/1630789773.pdfIn PDF document text
    • http://elcwma.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/nimexoluruzega.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/d55d520c288a8f725416ac447fbf1098/kebejuluxajafikusovu.pdfIn PDF document text
    • http://kfgame.snailgame.ru/upload/files/20210901101708.pdfIn PDF document text
    • https://fabriziochessa.it/userfiles/file/fisobuladise.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/16148b29762fd2---23071766873.pdfIn PDF document text
    • http://messtores.ca/fck_user_files/file/volepewi.pdfIn PDF document text
    • http://eyela.kr/uploadfile/fckeditor/file/sujelumuwexe.pdfIn PDF document text
    • http://everest-c.ru/ckfinder/userfiles/files/zuziguwin.pdfIn PDF document text
    • https://www.theknowledgeonline.com/files/lib/ckfinder/userfiles/files/13226541276.pdfIn PDF document text
    • http://proclima-membranes.ru/userfiles/file/xezirilipulonewegariko.pdfIn PDF document text
    • http://boothbayharborshipyard.com/userfiles/file/lalikoxuluzebazesixako.pdfIn PDF document text
    • http://studioarchterreni.it/userfiles/files/96279958332.pdfIn PDF document text
    • http://omni-links-europe.com/images/blog/file/97590457483.pdfIn PDF document text
    • http://azco.friend-match.com/upload/files/kuradideziximu.pdfIn PDF document text
    • https://nomaquito-travel.com/editor-images/turuki.pdfIn PDF document text
    • https://luxurytravel-show.com/wp-content/plugins/super-forms/uploads/php/files/9bf6a562b6d4e58047d33fe827c43bd0/pavafudopatijivakegisuwe.pdfIn PDF document text
    • http://teleserviciomalaga.com/ckfinder/userfiles/files/90599809330.pdfIn PDF document text
    • http://crossfit28.com.s125853.gridserver.com/siteuploads/editorimg/file/94895564410.pdfIn 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://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_off0000ea03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA03 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001021a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1021A 10644 bytes
SHA-256: ea4e1b85d45fe849348f6a3d886c3816d0d90524efe386c879311fed0e9f8ff7
font_02_sfnt_off00011a66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A66 17756 bytes
SHA-256: b0a218295a971b25281a916613a26d350ffea7d3704f7bc553d6ae2c42a5ba70