Malicious PDF — malware analysis report

Static analysis result for SHA-256 8eff69d73854bfcc…

MALICIOUS

PDF

92.8 KB Created: 2021-09-23 08:31:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 7dcbfda53e6f318a41f8d3653b43ecdd SHA-1: 48272898493a2dbdfc876688c9921f0278c20c0c SHA-256: 8eff69d73854bfcc5aeca80d44cb7bf692357deacc09df7f2246ac96d545cdbd
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which are part of a link farm hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The embedded JavaScript is likely used to facilitate the redirection to these malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9726

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://krisoc.ru/uplcv?utm_term=universe+android+app PDF link annotation
    • https://chambres-a-la-ferme-plouzelambre.fr/userfiles/file/10879513912.pdfIn PDF document text
    • http://smartvoicecom.com/userfiles/36551824558.pdfIn PDF document text
    • https://gelblighting.com/userfiles/files/38287243358.pdfIn PDF document text
    • http://www.dagmarsvendova.cz/admin/js/ckfinder/userfiles/files/40688877776.pdfIn PDF document text
    • https://parkettworld.com/upload/files/xizefufod.pdfIn PDF document text
    • http://cl-pub.com/files/files/kufaxupobobi.pdfIn PDF document text
    • https://its-bulgaria.bg/files/file/tufaxej.pdfIn PDF document text
    • http://el-system.jp/uploads/2012/files/334023105.pdfIn PDF document text
    • http://profstil.az/userfiles/file/51954490320.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b636866fc1---walopapexujematikaneleriz.pdfIn PDF document text
    • https://sangolongphuong.vn/longphuong/news/files/bisumi.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/16135e02901cb6---sukoxe.pdfIn PDF document text
    • http://videlec.be/ressource/file/36470786239.pdfIn PDF document text
    • https://quangcaowebsitecomvn.xemlaco.com/uploads/files/44734571372.pdfIn PDF document text
    • https://filetorme.com/upload/files/26949417182.pdfIn PDF document text
    • https://hzautomatisering.nl/userfiles/file/84734962235.pdfIn PDF document text
    • http://saveondealz.com/ckeditor/ckfinder/core/connector/php/uploads/files/10136266668.pdfIn PDF document text
    • http://honderhotel.com/UploadFiles/FCKeditor/20210913131159.pdfIn PDF document text
    • https://insinkerator.us/images/uploaded/file/dexido.pdfIn PDF document text
    • https://intersensor.ro/v2011/Files/fck_upload/file/90790680187.pdfIn PDF document text
    • http://elfuklid.cz/foto/Image/file/70877776430.pdfIn PDF document text
    • http://bualuang101.com/backoffice/upload/files/bozatajapakitesazofixo.pdfIn PDF document text
    • http://wmc21.com/ckupload/files/nemuwofitokanujaj.pdfIn PDF document text
    • http://geomanteia.com/userfiles/files/vedalofina.pdfIn PDF document text
    • http://th-hl.com///upload/files/22277790855.pdfIn PDF document text
    • https://thehouseconcert.com/ckfinder/userfiles/files/3981265744.pdfIn PDF document text
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f226.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF226 10312 bytes
SHA-256: 249833d70c90ff2f85a2f5637f64c9d65a023a5adb65012721c04b77a7f25bfd
font_01_sfnt_off00010978.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10978 17180 bytes
SHA-256: d25170a12664dd6bf87ab3ed0677d805d90724364a2a2448ec477d9aaa1d4d2f
font_02_sfnt_off000135ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x135CE 16448 bytes
SHA-256: 0e4cde3d5bdd5452960de995a4807c8da4ec665155a9812e2f8e54e6c49b7878
font_03_sfnt_off00014ca7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14CA7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1