Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b7baea9fae7c20d…

MALICIOUS

PDF

86.0 KB Created: 2021-05-04 05:35:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: 8cb31c96ad7e54d56cca7afe646bcc85 SHA-1: cd6b35b225b63f76631af3ed045f360066b227a3 SHA-256: 2b7baea9fae7c20d434c5b3eedf18030c2677152ba754623d04208d088202ef1
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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 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://vilenefex.ru/strik?utm_term=scary+stories+3+more+tales+to+chill+your+bones+table+of+contents PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4369768/normal_606c7d5b37585.pdfIn PDF document text
    • http://nicepics.xyz/46907082718bwoio.pdfIn PDF document text
    • http://ketrovk.xyz/income_statement_and_balance_sheet_template_excelj7fnz.pdfIn PDF document text
    • http://fokojudup.22web.org/gaxavixujevetatas.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459791/normal_6060ba8559451.pdfIn PDF document text
    • http://kdghy.online/agatha_christie_storiesc3l5x.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4423454/normal_6006a0dfc6d65.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4409609/normal_604057c81fca0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375341/normal_601a07233270f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4419857/normal_5fddbd587c1bd.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4401723/normal_5fc591ef3c273.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370319/normal_604fd1e9c2b6c.pdfIn PDF document text
    • http://stavki.link/daxogilufowolaruti9chwp.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470982/normal_60564ecab4250.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417308/normal_601f3f9cc99ce.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://6a421494-2577-4416-904f-e17348f56b63.filesusr.com/ugd/85e76a_c1e9d8dd21a34199bf4dfd5631bc6d65.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/a2c371a9-9916-4cce-b218-66730044ac5d/how_much_is_the_a10e.pdfIn PDF document text
    • https://5de9ed01-d610-4143-94db-6f998645a8ce.filesusr.com/ugd/1d8bf6_0b9275a0813a403eb3ff57dddb12385b.pdf?index=trueIn PDF document text
    • http://dusetelonuzaj.epizy.com/9850864854.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f632a495-3331-4c91-8c0f-5f5c040de990/2019_sat_math_2_practice_test.pdfIn PDF document text
    • https://288dffde-0386-48bd-adba-b069b5f3b70f.filesusr.com/ugd/7e1b39_d69a1e2761fe486ea1943c686b0d75a6.pdf?index=trueIn PDF document text
    • http://ninamivekadod.epizy.com/jarewerugukurom.pdfIn PDF document text
    • https://5dfb2dbd-6c80-4a99-afab-57dcddd938ef.filesusr.com/ugd/79d40d_ea0190055c634020ad120711e4db58ba.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/472f74e3-16a8-468f-9071-5b2cdd9b4447/lodajipadapowoturomatisi.pdfIn PDF document text
    • http://taxopewik.rf.gd/sowesubudaberuvexalenavu.pdfIn PDF document text
    • http://gapifemesi.rf.gd/email_writing_format_for_job_application.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_off0001109b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1109B 5628 bytes
SHA-256: d13bdfd865f9eeb8d7ea634f74868aa3a277bcbd20253a56b96b57b0d584a5f0
font_01_sfnt_off000123a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123A3 11184 bytes
SHA-256: 4b775716b44a508ac4a59578e87487e4d30dc982115dff8a449cf36b53e5d720