Malicious PDF — malware analysis report

Static analysis result for SHA-256 b99887a79f3ef0e9…

MALICIOUS

PDF

92.5 KB Created: 2021-09-13 03:03:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: afb18471145e2b09964821dc26992320 SHA-1: 728b589095356a731f942da8d78d51abba06c7f3 SHA-256: b99887a79f3ef0e9819dafea3e9be7b07bea81f6c819bc46056b0aceabdb9641
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which are hosted on disposable domains and appear to be part of a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded URIs suggest it's designed to lure users to external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 5

  • 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.
  • 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://crysiq.ru/uplcv?utm_term=what+is+corjet+vegetable PDF link annotation
    • http://marinaxaraes.com.br/ckfinder/userfiles/files/kiwono.pdfIn PDF document text
    • https://heritagecambodiatravel.com/userfiles/file/16644474944.pdfIn PDF document text
    • http://cristal-in.fr/userfiles/file/mefexexivuto.pdfIn PDF document text
    • https://www.wsbe17hongkong.hk/_bin/ckfinder/userfiles/files/vumugizadujewekiwezodij.pdfIn PDF document text
    • http://vilocom.net/webroot/img/files/22538714463.pdfIn PDF document text
    • http://ngoinvest.com/uploads/ckfinder/files/xazezijosakevivejeka.pdfIn PDF document text
    • https://dortmundpools.com/contents/files/lorubegem.pdfIn PDF document text
    • http://cesarrodarte.com/userfiles/file/vekituredonif.pdfIn PDF document text
    • http://pillshop.ru/uimg/files/wibozupadozoninij.pdfIn PDF document text
    • http://tostonet.cl/ckfinder/userfiles/files/1265823457.pdfIn PDF document text
    • http://studiosantomauro.it/userfiles/files/zenokidofakalekakuturiz.pdfIn PDF document text
    • http://nickels.design/ckfinder/userfiles/files/xazumokamikinokabej.pdfIn PDF document text
    • http://daydeothe.vn/rich_editor/file/pivapo.pdfIn PDF document text
    • http://villkasz.hu/editor_up/19565115470.pdfIn PDF document text
    • http://songdolandmarkcity.com/userfiles/file/7385865496.pdfIn PDF document text
    • http://bobhendrix-law.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/1807964047.pdfIn PDF document text
    • http://daejonggyoyc.com/userfiles/file/20210901173243.pdfIn PDF document text
    • https://tasivn.com/upload/ck/files/tixupizo.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/7d0036ff01231949fc2a1aed781e055f/77190590713.pdfIn PDF document text
    • http://pronobile.com/catalog/file/78855831893.pdfIn PDF document text
    • https://koncnc.com/genelresimler/file/56057548423.pdfIn PDF document text
    • http://romovi.net/sgi_userfiles/userfiles/files/guzedevafowawazamebukon.pdfIn PDF document text
    • http://ildungrice.com/fileupload/fckeditor/file/solelusobifiv.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000100b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100B2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000118c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118C9 10732 bytes
SHA-256: 7c185af2434fe73ce421b8fd61df6e717f52eacd760fa2a7328f260bb365f114
font_02_sfnt_off00013198.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13198 19900 bytes
SHA-256: 18f49f17e16ace8b4a3dbe52fde2b29c14d6d811e3a590149105d5b2df18a440