Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb90a4710f4381ad…

MALICIOUS

PDF

69.9 KB Created: 2021-09-24 14:13:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: b5e85bc928e4bc5db7cb61825f7dee99 SHA-1: b2f71410f4efe23d8424147596483304e74cf07d SHA-256: cb90a4710f4381ad02cf3a069743a13a9283ac1f6972c379564c113333ddf7ef
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains numerous embedded URLs, many of which point to compromised WordPress upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is unreadable, but the heuristic firings strongly indicate a phishing or redirection attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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://mega.kz/media/upload/files/75619827041.pdf In PDF document text
    • http://baltic-rt.ru/ckfinder/userfiles/files/33306223363.pdfIn PDF document text
    • https://cairparavel.ro/app/webroot/files/userfiles/files/57060914113.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149180622972---80896373280.pdfIn PDF document text
    • http://imreelectric.sk/uploads/file/89741014821.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614db040a8084---82298895815.pdfIn PDF document text
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/1614d65a688905---62429207560.pdfIn PDF document text
    • http://resheto.ru/users_images/fck/file/69425360872.pdfIn PDF document text
    • https://panama4d.com/contents/files/43726163409.pdfIn PDF document text
    • http://www.emporiocaritaspisa.it/wordpress/wp-content/plugins/formcraft/file-upload/server/content/files/1613f5b48a2465---34104453123.pdfIn PDF document text
    • http://gewidor-gmbh.de/uploads/files/95410834788.pdfIn PDF document text
    • http://wecans.net/_UploadFile/Images/file/saluxazu.pdfIn PDF document text
    • https://emmaushuis.org/pages/bujunexapujusuv.pdfIn PDF document text
    • http://mimarathi.live/assets/ckfinder/core/connector/php/uploads/files/batir.pdfIn PDF document text
    • http://kingswaytyres.com/project/kingsway/uploads/file/69582878078.pdfIn PDF document text
    • http://factblogs.com/uploaded_files/userfiles/files/nulemero.pdfIn PDF document text
    • http://law885995.com/upload/fckimages/file/50790565972.pdfIn PDF document text
    • http://taikenplan.jp/ckfinder/userfiles/files/90192945824.pdfIn PDF document text
    • https://fminterativa.net/cms/plugins/ckfinder/userfiles/files/doxovo.pdfIn PDF document text
    • http://klaaswester.nl/img/file/podediwoxowubez.pdfIn PDF document text
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/e0ffa1fp8n2tvcj69mb50oiv8p/karebapegal.pdfIn PDF document text
    • http://modelseafarm.com/kweb/ckfinder/userfiles/files/newubopodepil.pdfIn PDF document text
    • https://hankilfood.com/userfiles/file/20210904171526.pdfIn PDF document text
    • https://vietnam-pump.com/userfiles/file/zinaj.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/fesomexa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=droid+turbo+2+dimensionsPDF 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_off0000b03c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB03C 15812 bytes
SHA-256: dd98546549bb175ef793d33df4a4108d30cb64748f5b08c7a1ca18c83530e5d9
font_01_sfnt_off0000d86e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD86E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f085.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF085 10560 bytes
SHA-256: 983e54817711cb7cd114609924a7d0093a9ad091ffda6bebf2479ddc74870a7b