Malicious PDF — malware analysis report

Static analysis result for SHA-256 934cb975a9a3257a…

MALICIOUS

PDF

75.7 KB Created: 2021-06-10 09:59:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: 49ec66538c187acc0b5ae950e2683048 SHA-1: aa1f8b81e1b826f79bb2a2d5d1837dea5162d6cc SHA-256: 934cb975a9a3257a0aee1ab2d51b989fc7836b743d4e965195c6a776a0a54620
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, flagging it as a phishing trojan. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and other domains, likely intended to redirect users to malicious content or phishing pages. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, and the presence of embedded URLs and link farm heuristics strongly indicates a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://pistant.ru/uplcv?utm_term=free+letter+worksheets+preschool PDF link annotation
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096eb85a6258---nobuzanobewanatuvewa.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/os2328tqs8l251or0kmbrfl5ac/remegedojagusanegi.pdfIn PDF document text
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a50e7545226---20773406526.pdfIn PDF document text
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/1dc2e48aa389eeb22bfd666aec94db0a/38341878404.pdfIn PDF document text
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/5lkog3etqv0nl67cj9oavhp6b1/venudetevutorobok.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f413b2a154---sedizofitiruvovomujal.pdfIn PDF document text
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/792o3qfss3nftuu6aq65de4dc1/62000880601.pdfIn PDF document text
    • https://medsplus.us/admin/images/file/konokajurixub.pdfIn PDF document text
    • https://catequesisnavarra.org/guiarte_userfiles/files/muderabegiwovowij.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090d1a1c07e9---24960606336.pdfIn PDF document text
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/u4fvd9prmgkhi5oqv65dhfoor2/54528623060.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/16076f8e11e94b---84673593027.pdfIn PDF document text
    • https://www.hotwaterfactory.com.au/wp-content/plugins/super-forms/uploads/php/files/d47907e48f78348d9d1b738dfd6e58d0/gadoluvurejoporabuwevami.pdfIn PDF document text
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606d240abbe30---bugimivevemawej.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/8c1c12ee914ac111b49d09724b6ec681/nikexabubebaxekorogopet.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/160ba21e3aa0b5---65858952039.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_off0000ea4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA4F 4924 bytes
SHA-256: af4945a68f638d5524adeff4f075e7f25487c0e973e447699864d39523378d69
font_01_sfnt_off0000fb23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB23 10784 bytes
SHA-256: 30a5379246bd2c9d74cf727afaced6d4723b871f0c256fe3de320614e1417f50