Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3a56383515c2fb0…

MALICIOUS

PDF

71.5 KB Created: 2021-06-06 17:33:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d02ce95d443383b38902f3c42870d84e SHA-1: 317846bf06d7bfe547bac26db972771f57cec3bb SHA-256: b3a56383515c2fb096118f002b2d7245053a91f436c68af8125774522e099278
156 Risk Score

Malware Insights

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

The PDF document contains numerous links to external websites, many hosted on compromised WordPress installations, suggesting a link farm or phishing campaign. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with attempts to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://krisoc.ru/uplcv?utm_term=how+to+fix+virtual+background+in+zoom+without+green+screen
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/j7m0c746rejgvlglbcdhgm15qp/72113311479.pdf
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/3uoulmskhua0p3930dnjfe5q57/50175664375.pdf
    • https://maspacientes.es/wp-content/plugins/super-forms/uploads/php/files/0isnilp0638um36rtegjj724nr/pukanadilaxebelotojevipip.pdf
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/0gs1k5klsrlgefgtcjtn0e8880/minubataxesijoraxo.pdf
    • https://inchiriereelicoptere.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609d54be8f761---monumesusudizelexuni.pdf
    • http://www.dismaplant.com/ckfinder/userfiles/files/givaxizuwefagisesuw.pdf
    • http://aarogyamedico.com/userfiles/file/debixotekatibadamu.pdf
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/bacb5807b19a97df68273eab0cde43ee/benejexuxufewofajebon.pdf
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/d05cad4dee569c5ac96d514d054810df/vuvusetefo.pdf
    • http://ptk-astana.kz/wp-content/plugins/super-forms/uploads/php/files/019220577fc34678dd9b54ece38ed806/15929407122.pdf
    • https://fastcomputer.vn/wp-content/plugins/super-forms/uploads/php/files/5dd3dc1872d4a89bffdaafeb66dbf390/10167702231.pdf
    • https://nowbali.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/1607fb90d3aa86---24638878306.pdf
    • http://dhf-china.com/d/files/78784429468.pdf
    • https://elitteaccesorios.com/wp-content/plugins/super-forms/uploads/php/files/rl0t5gibbk7e7p1p0jrm7vm5a0/58184381365.pdf
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/114o4uviff9i9dtm5ns3c13nj5/gopapigewegezasatezofo.pdf
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16072947da8bcc---tekisigaruguxakixas.pdf
    • https://aedwea.com/upload/foto/95114868196.pdf
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098180ad3ca4---mamidowidabutoliwujiliz.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d739.bin
5e7ccfcc2360e8ef933f840da50dd6420aa5f68d062b42a5566d40c1caedd8e8
pdf-font-stream PDF embedded font (sfnt) at offset 0xD739 5872 bytes
font_01_sfnt_off0000eb2b.bin
20ca605035b821832468e3cdfaca0ec061aff91566b6786bcfc8a6ca600b08a0
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB2B 10404 bytes