Malicious PDF — malware analysis report

Static analysis result for SHA-256 a612752f5fa7fc2e…

MALICIOUS

PDF

90.6 KB Created: 2020-10-26 12:09:35 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-27
MD5: a5caa4d4667ebdb64ace9663b5cf226f SHA-1: 7de32c63670fabce65d588bff10918b552ebf3a5 SHA-256: a612752f5fa7fc2e4c41c0b87766ca1387435622a8f47113a282330d6e42d56b
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of embedded links, many of which point to suspicious or known malicious redirector infrastructure. The document body, though garbled, contains text related to 'Verbos en ingles y español regulares' and the authoring application 'wkhtmltopdf', suggesting a lure to a website offering language learning resources. The ML classifier strongly indicated maliciousness, and the PDF structure itself points to a link farm designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://cctraff.ru/strik?keyword=verbos+en+ingles+y+espa%25C3%25B1ol+regulares In PDF document text
    • https://cdn-cms.f-static.net/uploads/4369153/normal_5f8f981b344c4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379856/normal_5f92757dc710e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4371495/normal_5f8a4c480552d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4378599/normal_5f8ab1e75ecd8.pdfIn PDF document text
    • https://vewutaniwem.weebly.com/uploads/1/3/0/8/130873717/fd026ff.pdfIn PDF document text
    • https://duxebiforup.weebly.com/uploads/1/3/4/0/134013009/4b5b50661492439.pdfIn PDF document text
    • https://kuromazu.weebly.com/uploads/1/3/2/6/132695519/juwedegiduwelo.pdfIn PDF document text
    • https://zugufavowi.weebly.com/uploads/1/3/0/8/130874222/4900efd31424701.pdfIn PDF document text
    • https://saxibodusazo.weebly.com/uploads/1/3/0/7/130740440/5611588.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://cdn.shopify.com/s/files/1/0481/6093/1991/files/psiphon_mod_apk_updated_version.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/3310/0439/files/kopuzamewegiposapimujotu.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/5590/6967/files/vmd_user_guide.pdfIn PDF document text
    • https://s3.amazonaws.com/gorajikunobixi/radiance_alyson_noel.pdfIn PDF document text
    • https://s3.amazonaws.com/wiwamoxamo/gevijafinagubebugepaniru.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0484/0652/8152/files/brother_fax_2840.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0478/6280/8742/files/83737051121.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0501/8786/2194/files/62419417802.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off000062ea.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x62EA 63892 bytes
SHA-256: d30fd74866495c73ac2ce6ed86532476128b36b27a7782122abb9f60d1c7727a
font_01_sfnt_off00012302.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12302 5404 bytes
SHA-256: a4bc4bdbca08945941691b1b9f9c4fb7d11dc7b267c53f197fa50d7f8b014386
font_02_sfnt_off0001352f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1352F 11564 bytes
SHA-256: f9bcbc6a9e75c7451197ea2c941d266002411eff8d5521d4344449281cf866dc

Open this report in the interactive analyzer, or submit your own file for analysis.