Malicious PDF — malware analysis report

Static analysis result for SHA-256 c55c770b53c775a4…

MALICIOUS

PDF

70.0 KB Created: 2021-10-03 14:01:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: a8b0b3a233e8647993ef395ed0acfc03 SHA-1: eb89297892a91575eec0f045ef787addf0dfa8b4 SHA-256: c55c770b53c775a4e3e1e5754a39460d7f76a61fdc09331d16f3295939ccd4d2
156 Risk Score

Malware Insights

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

The PDF contains a link farm directing to numerous URLs, several of which are 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, but the heuristic firings and URL analysis point to a malicious link distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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 http://bright-mineral.com/uploadfile/file/2021090700583279.pdf In PDF document text
    • https://bunexim.dascalita.ro/app/webroot/files/userfiles/files/64390366562.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/55634668450.pdfIn PDF document text
    • http://permagnet.com/upload_files/file/210906042905496763tzkvkw.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614d4d1a6f42c---45554333661.pdfIn PDF document text
    • http://xedaptap.net/userfiles/file/50418454906.pdfIn PDF document text
    • http://e-sheremet.com/img/51713795739.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/161499d3dd11a2---gijulolikodej.pdfIn PDF document text
    • http://eptesteplelek.com/uploads/file/47762303608.pdfIn PDF document text
    • http://hanhthien.net/uploads/file/81689050554.pdfIn PDF document text
    • http://eot.mn/uploads/userfiles/files/93650802482.pdfIn PDF document text
    • https://ajansnigde.com/resimler/files/99812102259.pdfIn PDF document text
    • http://akademibt.com/resimler/files/24766785176.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161335a2e209fb---85924157172.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/1614bb51410ff3---xopanejofajimomofapares.pdfIn PDF document text
    • https://paymentor.nl/uploads/file/bujap.pdfIn PDF document text
    • http://indecomavo.pl/userimg/inc/dipatorato.pdfIn PDF document text
    • http://zehanbiopharma.com/upload/files/78518580907.pdfIn PDF document text
    • http://35ju.21tg.cn/uploadfile/ckeditor/files/97309822258.pdfIn PDF document text
    • http://goodslib.com/userfiles/file/12044285415.pdfIn PDF document text
    • http://nissanotogovap.net/uploads/images/files/mepuvigibeladijosuwilu.pdfIn PDF document text
    • http://hibertek.com/image/files/20210922_172120.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=cave+of+euripidesPDF 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_off0000b088.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB088 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c89f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC89F 10440 bytes
SHA-256: 6b3d8535a32a6bd5c3dee1a4f36c04269c2c8184c1278cdfafa18634a526146f
font_02_sfnt_off0000e072.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE072 16480 bytes
SHA-256: 337705ae9140d87514625eabbfc5ba76481d1f1d888218da6650f1158e133305