Malicious PDF — malware analysis report

Static analysis result for SHA-256 21f1b69dec54c98c…

MALICIOUS

PDF

74.8 KB Created: 2021-02-21 03:42:04 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-14
MD5: b6ea280654a84472387ed6588e13325c SHA-1: 2715ff68d70e1d448376b49049645b6a71fa215c SHA-256: 21f1b69dec54c98c53b551df2144294d4c3c09a218c43a005645e8fdc444d031
96 Risk Score

Malware Insights

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

The PDF document contains numerous external links, with a primary link to 'https://jacksth.ru/strik?utm_term=the+irishman+i+heard+you+paint+houses+title', suggesting a lure to a malicious site. The ML classifier strongly flagged this PDF as malicious, and the presence of a link farm heuristic further supports malicious intent. While no scripts were explicitly extracted, the PDF structure and link farm indicate an attempt to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 4

  • 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.
  • 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://jacksth.ru/strik?utm_term=the+irishman+i+heard+you+paint+houses+title PDF link annotation
    • http://povutigu.22web.org/bedijo.pdfIn PDF document text
    • https://serarabasujuz.weebly.com/uploads/1/3/1/6/131606617/pigotunenenukubavam.pdfIn PDF document text
    • https://diwijavel.weebly.com/uploads/1/3/4/6/134691177/zolelatuz-wepaw-lekikesedigi.pdfIn PDF document text
    • https://nufapapezo.weebly.com/uploads/1/3/0/9/130969462/ca031688b872a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4378171/normal_5fd61e32b89aa.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/juliziwojatige/form_pan_card_application.pdfIn PDF document text
    • http://banidokote.epizy.com/clerk_of_civil_district_court_cover_sheet.pdfIn PDF document text
    • http://lelixik.epizy.com/aspectj_eclipse_plugin.pdfIn PDF document text
    • https://s3.amazonaws.com/gopuze/plasticos_biodegradables.pdfIn PDF document text
    • https://s3.amazonaws.com/zeworibuzoza/insaniquarium_deluxe_free_online_games_no.pdfIn PDF document text
    • https://s3.amazonaws.com/goveruduzewoxu/besepozazulan.pdfIn PDF document text
    • https://s3.amazonaws.com/tasufagijaremo/is_capitalized_in_titles.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e834.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE834 5248 bytes
SHA-256: 3dad63a5befacf8267e10981529b0e4e8cdddcee5cc1c21947fdc60fbe6aa213
font_01_sfnt_off0000f9e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9E2 10740 bytes
SHA-256: 067279980ef6c4e3f4172f861ff56aaf4ece9993bb5521ff0d82ac3e1b85040f