Malicious PDF — malware analysis report

Static analysis result for SHA-256 91dee319c17717b2…

MALICIOUS

PDF

74.3 KB Created: 2021-06-13 17:12:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: 0bb9340bb608a60b81410bbad1eb09f5 SHA-1: 02df6137198abcab87991113ea6cf2c64b1c6de9 SHA-256: 91dee319c17717b23fea887daa4eb1793233e36791c3223252e60f7060556345
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains numerous links pointing to compromised WordPress sites, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of multiple external URIs and compromised CMS upload links supports this assessment.

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
  • 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://synerhu.ru/uplcv?utm_term=ninjago+season+15+episode+4 PDF link annotation
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607fdec347143---wimatunipogadadodu.pdfIn PDF document text
    • https://trellisdundee.com/wp-content/plugins/super-forms/uploads/php/files/20f83cd9bf3abbbe68ce5366cec7efe6/90174812417.pdfIn PDF document text
    • http://mattstergamer.com/wp-content/plugins/super-forms/uploads/php/files/lm3buudaq3d0gau2r9r4j0ptfs/89980274749.pdfIn PDF document text
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/136e74eaedc1be43639acd4c85b7853d/40976137353.pdfIn PDF document text
    • https://audreyheselmans.com/_files/file/kowemus.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160c43d5fd74ba---ropazisesunoveruzizo.pdfIn PDF document text
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/7m764pa01k81t1u7d08vg7p9cb/fevevexolujifutidurojam.pdfIn PDF document text
    • https://sitpchemcieszyn.pl/_sitpchem/file/tifatunonojufiba.pdfIn PDF document text
    • https://xn----7sbbjg7ctfs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/329619adf4384ee2061be089c4ce0f01/suxijenakuxanej.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b0312601802---gukusujofarodu.pdfIn PDF document text
    • http://www.studiolegalefusimorelli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609090b9bf538---40002895252.pdfIn PDF document text
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/160738ca3d8013---37214665656.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16072b889917f8---24337498841.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083e07ce7fae---sutukoduwiban.pdfIn PDF document text
    • https://londonvipchauffeur.co.uk/wp-content/plugins/super-forms/uploads/php/files/25ae8d211d0ea7e5cff97f594ad71f7b/wolinawodasokoxiwapak.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_off0000e313.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE313 5308 bytes
SHA-256: d35d6c6b7c14f75b0572be9f73597e95901bde81452cd01ce294071ea9c63df5
font_01_sfnt_off0000f550.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF550 11540 bytes
SHA-256: 0b2a6441f209e053c61d4bb61a1d3b2318164cc76ea87f3665ff0e9776d602e9