Malicious PDF — malware analysis report

Static analysis result for SHA-256 c878e65f50353ffe…

MALICIOUS

PDF

72.7 KB Created: 2021-09-29 14:49:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 8a34cf26390d7a32b4dd86e7f5624e15 SHA-1: 2b188653187aa976197d768272dedd7482f01fdb SHA-256: c878e65f50353ffe1a1232e44ef6a48b0b113b9c7daa05a8ede4f6ea82e113f7
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains embedded JavaScript, which is a common technique for executing malicious code within PDFs. The document also hosts a large number of external links, many pointing to PDF files on potentially disposable domains, indicating a link farm or redirection scheme designed to obscure the ultimate destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9827

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
  • 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 http://zs-g.jp/app/webroot/js/ckfinder/userfiles/files/85750307837.pdf In PDF document text
    • http://studiotecnicobergamaschi.it/userfiles/files/zodutipusodab.pdfIn PDF document text
    • https://yifff.se/userfiles/file/63254616229.pdfIn PDF document text
    • http://exosushi.com/uploads/files/75814686055.pdfIn PDF document text
    • http://lanaecoloridabruzzo.it/userfiles/file/92804362761.pdfIn PDF document text
    • https://catequesisnavarra.org/guiarte_userfiles/files/49245941602.pdfIn PDF document text
    • http://heydarbaba.org/resimler/files/molixutole.pdfIn PDF document text
    • http://noithatphathuy.com/Images_upload/files/meliwuw.pdfIn PDF document text
    • http://jszl-rolls.com/filespath/files/20210926063438.pdfIn PDF document text
    • http://www.saito-ken.jp/userdata/file/54813086706.pdfIn PDF document text
    • http://nawaress.com/webroot/js/ckfinder/userfiles/files/paxumatanokuzojitefidoso.pdfIn PDF document text
    • http://julianina.dk/upload/file/42773865074.pdfIn PDF document text
    • http://maquinandoysubastando.com/dleyes/admin/fotos/file/16402563424.pdfIn PDF document text
    • http://globalfeedindustry.com/upload/files/gitozutetomamugepe.pdfIn PDF document text
    • http://sziszolg.hu/editor_up/toxajogetadikopubitomatol.pdfIn PDF document text
    • http://nitecoreromania.ro/files/file/84865234012.pdfIn PDF document text
    • http://cdseoulps.com/uploadfile/fckeditor/file/75436607097.pdfIn PDF document text
    • http://www.morrisjones.co.uk/EditorImages/file/37751429469.pdfIn PDF document text
    • https://durgabas.coop.np/ckfinder/userfiles/files/gotukegipenitimuxuwe.pdfIn PDF document text
    • http://herborgthailand.com/file_media/file_image/file/vawepiwapaj.pdfIn PDF document text
    • http://imssp.by/data/images/fxeditor/file/40878446764.pdfIn PDF document text
    • http://studiogaleazzo.eu/userfiles/files/48322600251.pdfIn PDF document text
    • http://restokrat.info/userfiles/file/78156256461.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/c37115fc41a6b0a609eca4d2c0730e8e/wamomawojawip.pdfIn PDF document text
    • http://dietetyka-24.pl/images/files/20991856408.pdfIn PDF document text
    • http://bamboomfi.com/htdocs/cljr/data/files/17355741950.pdfIn PDF document text
    • http://albarossa.jp/js/upload/files/35187567125.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=sexual+words+beginning+with+rPDF 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_off0000b5c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5C1 18120 bytes
SHA-256: 24463cddddc31d1c1271428f2bfe965a1dfb3bbdf645e7d8081d8352284af665
font_01_sfnt_off0000e3f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3F2 11028 bytes
SHA-256: bc960c6d474f6cc194fb3f34e3206a7e3bf105f208ff8166cddcaf29eee6e5b7
font_02_sfnt_off0000fd5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD5D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1