Malicious PDF — malware analysis report

Static analysis result for SHA-256 905f4e5c4d28ec9c…

MALICIOUS

PDF

79.5 KB Created: 2021-09-23 11:58:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 0f4a5951d3c0ba0dbbf9a7ad71f3fede SHA-1: 7efa5e96b8544ffaf4cf74226ee0e5d213390708 SHA-256: 905f4e5c4d28ec9cb5ca24f9d7b5fec03d0244d849c3be95b5ee076f9ebeedfa
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress sites and other potentially malicious URLs. The presence of numerous links on disposable hosting suggests an attempt to obscure the true destination or distribute malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146ad8e08376---78342461970.pdf In PDF document text
    • https://wtmasonry.com/ckfinder/userfiles/files/nexusalutadajunogixanes.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/161427b7fe282a---busizefugusanow.pdfIn PDF document text
    • http://trubaopt.ru/content/file/tekokalujelemirowumunidij.pdfIn PDF document text
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/b9bbd9cbdf36af1cda1822e543f9435b/45244792295.pdfIn PDF document text
    • https://liur-krd.ru/userfiles/file/29033402887.pdfIn PDF document text
    • http://midoriku.zaitakunet.jp/app/webroot/upload_images/files/40836167182.pdfIn PDF document text
    • http://mevlanaasm.com/resimler/files/75668026039.pdfIn PDF document text
    • http://sangjeom.com/userfiles/file///62838018561.pdfIn PDF document text
    • https://castilloexterior.net/ckfinder/userfiles/files/89767364228.pdfIn PDF document text
    • https://h1t-urlaurora1-turbo.com/contents/files/nuvadala.pdfIn PDF document text
    • http://phupmirpol.pl/userfiles/file/rodewujiwuwaf.pdfIn PDF document text
    • https://adium.ru/userfiles/file/16727911484.pdfIn PDF document text
    • https://www.breastcancerfoundation.in/wp-content/plugins/super-forms/uploads/php/files/dcf2ab5b9d779ae877393997f08d6d59/76073728810.pdfIn PDF document text
    • https://leonardscopysystems.com/home/leonards/public_html/ckfinder/userfiles/files/19889689314.pdfIn PDF document text
    • https://bimstudioinc.com/media/files/23601183702.pdfIn PDF document text
    • http://topimmigrationlawyer.org/ckfinder/userfiles/files/fudugodilisig.pdfIn PDF document text
    • http://marasintl.com/public/ckfinderuploads/files/31071970864.pdfIn PDF document text
    • https://lazerom.pro/media/file/67335523523.pdfIn PDF document text
    • http://cartopack.be/Images/file/74636306614.pdfIn PDF document text
    • http://stamforgtechnologies.com/uploads/98237793042.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=watch+fear+the+walking+dead+season+4+episode+1+online+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_off0000d10c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD10C 11200 bytes
SHA-256: 801d98a9b91d6f200e58c5e76c738e37fdf02ed5cf63253fa0b8a15bc8c3111a
font_01_sfnt_off0000eb29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB29 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001033b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1033B 17104 bytes
SHA-256: e072d0c9e2fb04b5d8dcb185d5cb467cc95b2c73a4a6bc885e3955a1e8e3ee87