Malicious PDF — malware analysis report

Static analysis result for SHA-256 53591eb3157377c4…

MALICIOUS

PDF

84.2 KB Created: 2021-09-13 14:56:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: dd71f0db57a39b6e984f26ef92f21ec9 SHA-1: 174d61d59bc6186364b3a2f81a088ad43e552520 SHA-256: 53591eb3157377c4df8f36901f80e52a77825b41c756aefeff33eb734a5a685b
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains embedded JavaScript, which is often used to exploit vulnerabilities or redirect users. The PDF also functions as a link farm, hosting numerous URLs that point to other PDF files, suggesting a multi-stage download or redirection scheme. The presence of embedded JavaScript and numerous external links indicates an attempt to deliver a malicious payload or phish users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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 http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a6c5b9a5c0---babavajosipupapuno.pdf In PDF document text
    • https://presstone.hu/userfiles/file/bafadofogeduzukadeze.pdfIn PDF document text
    • http://www.americaninvest.net/upls/files/10034301151.pdfIn PDF document text
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/49dtvirgt27p3quu81o66266i0/feketotedusufofufurotob.pdfIn PDF document text
    • https://leo.tw/upload/ckeditor/files/somutabugabotererelalu.pdfIn PDF document text
    • https://wendi101.com/userfiles/file/lilafesoz.pdfIn PDF document text
    • http://vuason.vn/upload/files/konajolo.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/63713026694.pdfIn PDF document text
    • http://autowassenindex.nl/images/uploads/gunisematezap.pdfIn PDF document text
    • http://www.enfersalus.com/ckfinder/userfiles/files/66529374328.pdfIn PDF document text
    • http://szilasfood.hu/pic_upload/files/42708870647.pdfIn PDF document text
    • http://topoint.net/userfiles/fckFile/20210913071237.pdfIn PDF document text
    • http://bukharaatlanta.com/sites/default/files/file/jodujafivufu.pdfIn PDF document text
    • http://happyorderfood.com/uploads/files/wikomebipubajejupekujoja.pdfIn PDF document text
    • http://venusland.vn/app/webroot/img/files/51213453295.pdfIn PDF document text
    • http://jcpingie.be/public/files/63968260240.pdfIn PDF document text
    • http://cardealer-space.com/js/upload/files/suferupanom.pdfIn PDF document text
    • http://gabident.pl/local/userfiles/file/zitelopemorenorupoku.pdfIn PDF document text
    • http://shengyaweb.com/uploadfile/file/2021090216014942.pdfIn PDF document text
    • http://chongqinghaohong.com/upload/files/jupupeviras.pdfIn PDF document text
    • http://mebel-moscow.com/content/xuploadimages/file/82414518389.pdfIn PDF document text
    • http://baheth24cars.com/ckfinder/userfiles/files/97271139267.pdfIn PDF document text
    • https://encoyun.com/calisma2/files/uploads/rabuvabelikewobe.pdfIn PDF document text
    • http://sochisushi.nl/survey/userfiles/files/jivodese.pdfIn PDF document text
    • http://siciny.eu/userfiles/file/kigut.pdfIn PDF document text
    • http://jd6618.com/jd6618/file/2021-9/file/LwpCms2021_09_08_10_31_57_9722.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=redmi+note+10+camera+pixelPDF 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_off0000e372.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE372 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fb84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB84 18060 bytes
SHA-256: c01c682ae7174e5c3b577d1ea0f19a6e9b3806c2a587878be7c335e31143dbf8
font_02_sfnt_off00012a63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A63 10828 bytes
SHA-256: 4d23d3d9ba7dd2b600f1fb5043c89a615ed7f309acf5e18df93c8f0d2c2e3f29