Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ae957bd7b34952a…

MALICIOUS

PDF

67.9 KB Created: 2021-05-06 09:16:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: 8bb0ecc93e583ca709fc1b66469c0a48 SHA-1: 98f5ab51f39f66199ab29298bf31bc7e4692e941 SHA-256: 4ae957bd7b34952a9c218c791a4735db37b0e7f87a7117b81619eb62940c3bb1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9825

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://krisoc.ru/uplcv?utm_term=aprender+ingles+rapido+gratis+pdf PDF link annotation
    • http://vietxetai.com/wp-content/plugins/super-forms/uploads/php/files/hats89bk57po3n7q2n4gppbq0p/5047866783.pdfIn PDF document text
    • https://www.waterlooarmsnewforest.co.uk/wp-content/plugins/super-forms/uploads/php/files/ddcfea124a416cf91b0a87a219984319/jivagaxizekanezenuzesixem.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16077d6a3c136e---4648116232.pdfIn PDF document text
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ce99ce39df---59961936788.pdfIn PDF document text
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/it87jto819nauu0j0gd75bg4c0/mexuvafimar.pdfIn PDF document text
    • https://sasalidayanisma.org/uploads/file/tajimuferesenoku.pdfIn PDF document text
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16084b6abc9cd2---mikewux.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/buxewama.pdfIn PDF document text
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/0ec1d073583dbafe9c7f254ae70a829f/rifove.pdfIn PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070f54867d8e---5380464817.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085e4d9967e5---kebirofilavelebume.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a1bb763005---poronibupopelomidajim.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608b377998a36---3042995809.pdfIn PDF document text
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/130daf7f47bce40bfc35b73b99ca978d/dobegelibisododenuxik.pdfIn PDF document text
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091d18c5feb8---batekum.pdfIn PDF document text
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/4c804bebbfa55eb01bf9395beb4b6110/bosoferamesopokolobipi.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ca4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA4B 4988 bytes
SHA-256: 2431996cc6b5c30601115811e643eb330cc7667e8b2fe465c2946b4a463331fd
font_01_sfnt_off0000db49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB49 10680 bytes
SHA-256: d1c09d3db5da0581eff321ff0549c2d2466eedb540ae24dc3798bd37fd5ad015
font_02_sfnt_off0000fe19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE19 4324 bytes
SHA-256: ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3