Malicious PDF — malware analysis report

Static analysis result for SHA-256 6278dd879086c2e2…

MALICIOUS

PDF

119.7 KB Created: 2021-09-19 17:58:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6f15c9082f7a70a0d87afa6b97a90ec6 SHA-1: e0f94fec3a2a5caab4520a0747d4ae9a3c0587d3 SHA-256: 6278dd879086c2e250b05f7c8fdb95a027ef9d2a7e48410fc13d775ec2577983
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to websites hosted on compromised CMS platforms or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or to serve as a distribution point for further malware. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for human readability but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://asiancfea.org/userfiles/file/53402936002.pdf In PDF document text
    • https://mimpiindah1.com/contents/files/sovewul.pdfIn PDF document text
    • https://fainitelecommunication.com/public/editorfiles/file/81611384563.pdfIn PDF document text
    • http://learningkey.org/userfiles/31240982851.pdfIn PDF document text
    • https://glearningsolutions.com/userfiles/files/xorozuraraxosabofefo.pdfIn PDF document text
    • http://joyearland.com/ckfinder/userfiles/files/40086817163.pdfIn PDF document text
    • http://ecogestval.com/userfiles/file/38883807885.pdfIn PDF document text
    • https://fitness-sport.it/userfiles/file/69051138358.pdfIn PDF document text
    • http://abwingsbuffalo.com/uploads/files/donezebokidewarogorij.pdfIn PDF document text
    • https://tepatsasaran.com/contents/files/kekejobokazubo.pdfIn PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613be598885da---pagazasanon.pdfIn PDF document text
    • http://cl-pub.com/files/files/76857969181.pdfIn PDF document text
    • http://solarexperten.ch/fckeditor/editor/images/file/90791990389.pdfIn PDF document text
    • http://leprofit.ee/cmsfile/contentfiles/28218147328.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16138c0fa4636f---17631890797.pdfIn PDF document text
    • http://taxilitomerice.cz/ckfinder/userfiles/files/77002732787.pdfIn PDF document text
    • https://rts-wm.com/ckfinder/userfiles/files/rejigimizememewazamed.pdfIn PDF document text
    • http://3e-machinery.ru/app/webroot/filesfiles/75373965956.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/rjkatsasmtom89eu9tnt78navt/49500209514.pdfIn PDF document text
    • http://hcstonetw.com/uploads/files/202109180834063641.pdfIn PDF document text
    • http://dtjxbpzx.com/filespath/files/20210910155355.pdfIn PDF document text
    • http://thietbimaugiao.vn/Images_upload/files/vinugufawoba.pdfIn PDF document text
    • http://sun-eko.eu/files/file/bipedejanazoso.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=american+english+file+2+workbook+2nd+edition+teacherPDF 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_off0001664b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1664B 21580 bytes
SHA-256: 1a7523d9a81fa16a144db3758de018c72e8f17b3bf42a632244880efa02fb56a
font_01_sfnt_off00019deb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19DEB 11344 bytes
SHA-256: b1dae7582fdc7f121ceb0a58a1fd1ef90c83294a409531e1bbc7224a03d75c0e
font_02_sfnt_off0001b855.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B855 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1