Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b692fc2ff9cba0e…

MALICIOUS

PDF

110.2 KB Created: 2021-08-04 18:16:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7493607fd1bf48ca9f72a8203ec04509 SHA-1: bdcc2d386b639883b4e656cdb5c1284797a16cfd SHA-256: 3b692fc2ff9cba0ec6c33aa6ce5e879db100641cfa10b46755e64977c5dc03a9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to external sites, some of which are hosted on compromised WordPress installations. The PDF structure suggests it functions as a link farm, likely intended to redirect users to phishing pages or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://cructi.ru/uplcv?utm_term=%D1%81%D0%BA%D0%B0%D1%87%D0%B0%D1%82%D1%8C+%D0%BC%D0%BE%D0%B4%D1%8B+%D0%BD%D0%B0+%D1%81%D1%82%D0%B0%D0%BB%D0%BA%D0%B5%D1%80+%D0%B7%D0%BE%D0%B2+%D0%BF%D1%80%D0%B8%D0%BF%D1%8F%D1%82%D0%B8+%D0%BD%D0%B0+%D0%BC%D0%B0%D1%88%D0%B8%D0%BD%D1%8B
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160dfb1527e9c3---70244971550.pdf
    • https://sport-jicin.cz/dokumenty/2970300204.pdf
    • https://harrisitalia.it/uploads/file/gakibewawelanenebokinuwiw.pdf
    • http://rkmaster.ru/uploads/files/sipidunadukaxag.pdf
    • http://czdashan.cn/uploadfile/file/2021043004091373499.pdf
    • http://nano-vip.com/ckfinder/userfiles/files/44642675549.pdf
    • http://biancoacolori.it/userfiles/files/duravisot.pdf
    • http://contentworks.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160d651fdb93bd---90362467848.pdf
    • https://balajitutorial.com/admin/userfiles/file/birojus.pdf
    • https://inncredel.com/uploads/mefujosadujane.pdf
    • http://adabaskimerkezi.com/upload/file/71077409621.pdf
    • http://bkdesign.ee/userfiles/file/5316707489.pdf
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096749b45cd9---wawavivekoviremuvawuj.pdf
    • https://weeb.nu/userfiles/file/23103016778.pdf
    • http://artospace.com/pics/file/vutezisexux.pdf
    • https://salvamontbihor.ro/app/webroot/files/userfiles/files/37202309832.pdf
    • http://abwalabamaave.com/uploads/files/wavonol.pdf
    • https://i3mit.com/shopadmin/upload/files/91298704985.pdf
    • http://robertfeinberglaw.com/images/edit_images/file/68053718022.pdf
    • https://bitree.ru/ckfinder/userfiles/files/tilidigupedarepuxuvis.pdf
    • http://ekvatorbl.com/userfiles/file/xojipibizomil.pdf
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/3d8ec8ad36d5fb96b4ba44decdd18b6d/57794846130.pdf
    • https://www.ideaklinik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f73df73e0d---72061461917.pdf
    • https://anandamsanyal.com/userfiles/file/dofiveresaxezujetovaba.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000137a1.bin
6b90c5340fcb77ab6b8fcd2cbb05e84bebf6833c73645186b9abe706c8394d2a
pdf-font-stream PDF embedded font (sfnt) at offset 0x137A1 11336 bytes
font_01_sfnt_off000151d6.bin
e5f1ec780dc52124a770afdcf32779c3c23105beffadb1b96795463925ed8322
pdf-font-stream PDF embedded font (sfnt) at offset 0x151D6 24744 bytes
font_02_sfnt_off00018f88.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x18F88 16792 bytes