Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a6fb8e496831fc1…

MALICIOUS

PDF

82.7 KB Created: 2021-05-30 20:41:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: bbca9b4e2a7424807382ef1d1f4c80a7 SHA-1: 25b88e1e4324774e06d7217bdc4d72018687d6cc SHA-256: 5a6fb8e496831fc16b80e5db5ea9050eca55bdbd2cfee550b7b9a9f095821518
186 Risk Score

Malware Insights

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

This PDF file contains a large number of external links, many hosted on disposable domains, indicating a link farm designed to redirect users. The presence of a URL pointing to 'jacksth.ru' with a query parameter suggesting a download or access action further supports this. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 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.
  • 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://jacksth.ru/strik?utm_term=%25D1%2581%25D0%25BA%25D0%25B0%25D1%2587%25D0%25B0%25D1%2582%25D1%258C+%25D0%25BE%25D0%25B1%25D1%2580%25D0%25B0%25D0%25B7%25D0%25B5%25D1%2586+%25D0%25B4%25D0%25BE%25D0%25B3%25D0%25BE%25D0%25B2%25D0%25BE%25D1%2580%25D0%25B0+%25D0%25B0%25D1%2580%25D0%25B5%25D0%25BD%25D0%25B4%25D1%258B+%25D0%25BA%25D0%25B2%25D0%25B0%25D1%2580%25D1%2582%25D0%25B8%25D1%2580%25D1%258B+%25D0%25BF%25D0%25BE%25D1%2581%25D1%2583%25D1%2582%25D0%25BE%25D1%2587%25D0%25BD%25D0%25BE PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4465006/normal_5fec101cc296a.pdfIn PDF document text
    • https://didunebufanef.weebly.com/uploads/1/3/4/6/134680758/fezem.pdfIn PDF document text
    • https://senorori.weebly.com/uploads/1/3/4/6/134641151/1766155.pdfIn PDF document text
    • https://febosefukeja.weebly.com/uploads/1/3/5/3/135324858/5ab61fac3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4382953/normal_606894e7c479d.pdfIn PDF document text
    • https://gojenegitoz.weebly.com/uploads/1/3/4/3/134387591/faxil.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4369660/normal_5fc9778911917.pdfIn PDF document text
    • https://jokilexagazoxo.weebly.com/uploads/1/3/4/6/134602179/siposiwonosu_bopunafegulox.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4373271/normal_606d1fc9292f1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4409997/normal_602011de9e4b9.pdfIn PDF document text
    • https://reninifovebomul.weebly.com/uploads/1/3/4/3/134361606/8e8bde779d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4487187/normal_5fd9932f15484.pdfIn PDF document text
    • https://pipenibeteza.weebly.com/uploads/1/3/4/5/134508730/4074096.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387562/normal_60469c4c8fbe9.pdfIn PDF document text
    • https://worubagazew.weebly.com/uploads/1/3/4/6/134639575/2f54e09f1.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4391008/normal_5fc7aa0948473.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4421939/normal_5fdd862647422.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375075/normal_6035dd1b8de98.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4409621/normal_601e41d60136b.pdfIn PDF document text
    • https://xukopalobupekon.weebly.com/uploads/1/3/4/7/134730613/gaxedefolo-vebowiz.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off0000f4e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4E4 6224 bytes
SHA-256: ac1fe655fe69885fe9e8291074776b5f53656ae6f2b81d295fb914ddce72365c
font_01_sfnt_off00010926.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10926 15632 bytes
SHA-256: 990c2f197024bc20a3fa13564851eda5f5ca26624186682deed6749867c069cb