Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9997a3d25312598…

MALICIOUS

PDF

79.1 KB Created: 2021-08-20 03:26:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: f11a59901f4a8f8bbaf80711572206c1 SHA-1: 6aa6628f615f8069dac25ffde23f53e569277e21 SHA-256: a9997a3d25312598e76f88e39c1712133bc76514f40213f224807fa1a7484164
156 Risk Score

Malware Insights

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

The PDF file contains a link farm directing users to multiple URLs hosted on compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is unreadable binary data, but the heuristics and URLs confirm its function as a malicious link aggregator.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://cdpu.net/wp-content/plugins/super-forms/uploads/php/files/a58ce9c7b2170cd6ddfd9b1e8cdcbe4f/xopaxajanawuxubazafofifu.pdf In PDF document text
    • https://www.zaantraining.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608e14d901b5a---bezip.pdfIn PDF document text
    • https://burgaseguros.com/userfiles/file/fofinufiwipajog.pdfIn PDF document text
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/62f9fe590109ac4104b6e41fafdb6b27/86334462693.pdfIn PDF document text
    • https://europeancustomtailor.com/wp-content/plugins/super-forms/uploads/php/files/21e43f5777213c6b28fad0c45757aa1a/86985241968.pdfIn PDF document text
    • http://shopsuathientu.com/uploads/userfiles/file/75436998726.pdfIn PDF document text
    • http://spain-ex.com/images/blog/file/15946301213.pdfIn PDF document text
    • http://www.alexgis.com/siteuploads/editorimg/file/tutasudonikafidik.pdfIn PDF document text
    • http://krupongs.com//images/file/powizowejowire.pdfIn PDF document text
    • http://shengnabei.com/uploadfile/file///2021081807291860.pdfIn PDF document text
    • http://brenna-ski.pl/userfiles/file/bifonetudiw.pdfIn PDF document text
    • https://otelnamore.com/wp-content/plugins/super-forms/uploads/php/files/7cde4318f1f9cd8a373b16d38a6ecf7a/4406595559.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/vhamqin0njva0qvihjblqf9pcl/59156638486.pdfIn PDF document text
    • http://amy-tsai.com/images_express/userfiles/files/65597601020.pdfIn PDF document text
    • http://banghetretunhien.com/media/ftp/file/logonuvizumimitubetitojiw.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160faf31391518---vikemabidemevukep.pdfIn PDF document text
    • http://nhandieurangmuoi.com/ckfinder/userfiles/files/6295181782.pdfIn PDF document text
    • http://sibservis.com/ckfinder/userfiles/files/pewetivixefopolasulol.pdfIn PDF document text
    • http://www.ks-zahnarztpraxis.de/upload/files/85096881665.pdfIn PDF document text
    • http://geopraxis.it/userfiles/files/desekipe.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/8cb52f078aef57cf371d4a115174c966/visolunidisum.pdfIn PDF document text
    • http://bacvietexpress.com/upload/userfiles/files/79590872618.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=esen+yay%C4%B1nc%C4%B1l%C4%B1k+indirPDF 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_off0000d013.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD013 18664 bytes
SHA-256: ba5f42ee08cd7f33fa1b041feeb856be90bb07cab1bdae62172410ba0577a79d
font_01_sfnt_off0000fdb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDB1 10380 bytes
SHA-256: 74f7658e40a3406f1f58a9e3f9190bee997e2b2ab08a36b9fc741d6a3acf15fe
font_02_sfnt_off0001152a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1152A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1