Malicious PDF — malware analysis report

Static analysis result for SHA-256 6591ceb9309f2c14…

MALICIOUS

PDF

89.4 KB Created: 2021-06-23 09:32:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-05
MD5: 898ad3702c4797592eee9af79d7164b9 SHA-1: bc5543c45fe67972ba92e8f68869aa8d946ee672 SHA-256: 6591ceb9309f2c149312f10fbfaae768aa0d348cdd3a56673428643b7c232ed0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by multiple heuristics as malicious, including a ClamAV detection for 'Pdf.Phishing.Trojan'. It contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users. The ML classifier also strongly indicated maliciousness. The primary attack pattern involves directing users to external sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • 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://irlanc.ru/uplcv?utm_term=o+capitalismo+tardio+mandel+pdf PDF link annotation
    • https://www.duffylighting.com/wp-content/plugins/super-forms/uploads/php/files/fe3091afe3ece394dc10bb6077c19350/39395954555.pdfIn PDF document text
    • https://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0bf9d0363e---girapewafadagumukofumawe.pdfIn PDF document text
    • http://sacoorhealth.pt/site/upload/file/64802617515.pdfIn PDF document text
    • http://eurogeographyjournal.eu/admin/fckfiles/file/35065689817.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/9e2282c306513978e27706002c466172/94851542504.pdfIn PDF document text
    • http://pensacolahigh1964.com/clients/1/1d/1d652d7f5bd5fd2f3712913460b20393/File/16180786599.pdfIn PDF document text
    • http://www.cenlaenvironmental.com/siteuploads/editorimg/file/16372364059.pdfIn PDF document text
    • http://kusadasidentalclinic.com/img/userfiles/files/60638797700.pdfIn PDF document text
    • https://socialchangefactory.org/wp-content/plugins/super-forms/uploads/php/files/6fe057c877ba9bf5d582f8636a42e9a3/lejemonizurizetado.pdfIn PDF document text
    • https://windsbs.biz/files/file/wosoginabokex.pdfIn PDF document text
    • http://xn--939a66v0zjo3bcvdmrp.com/data/ckfinder/files/zelunigozevolelibumobiri.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/026eaf0e781ac5adbd48e413ad526b09/jalodobisozexogujaluk.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/c07631b74b53ec8798472bcf06e1349d/bogubaropinubonisumugewo.pdfIn PDF document text
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/0rqeor3npnj2lc3qn987ddbdk2/53819741732.pdfIn PDF document text
    • https://liniagdanskzydowo.pl/files/vulukusijowuxejoximakug.pdfIn PDF document text
    • http://ttmplus.com/userfiles/files/68209257281.pdfIn PDF document text
    • http://kimyasaldubeller.com/upload/ckfinder/files/3190359016.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010544.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10544 5328 bytes
SHA-256: 8ecb21b30e8b9c0179a4f57f98c6cee6b8d2913ae5c7fc8586cd0615fa225d28
font_01_sfnt_off00011746.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11746 13888 bytes
SHA-256: 04662dcdf6f80339f5f01de13f5b2bc62b48e737f47b3d18409cc9b97f6c06e1
font_02_sfnt_off000142fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x142FE 16204 bytes
SHA-256: a95eff378c135b1ab40d10b3cd1da1bafbc07f86005f57898d079c90d712ddbd