Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a3ea62b808fc0fd…

MALICIOUS

PDF

65.6 KB Created: 2021-06-15 13:46:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: a25b3156fead1da98fac7533d88456e8 SHA-1: 3d589c1e8efde8aaff918268a4d769bb8481f458 SHA-256: 1a3ea62b808fc0fd1e893fa263d3a894b63911aa04768eab9b04ea22aba64737
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous external links, many hosted on compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The document body itself is heavily obfuscated and appears to be generated by wkhtmltopdf, further obscuring the true purpose.

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://medvor.ru/uplcv?utm_term=prepositions+fill+in+the+blanks+worksheets+pdf PDF link annotation
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/o8dgnatp64io4t2u72j0e7a3j9/jezexuroliwisefa.pdfIn PDF document text
    • http://xn--om2b25zm6igqb.com/ckupload/files/zexerubobifarif.pdfIn PDF document text
    • http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/nripe8ipu5qo0hfsmgl1t9rco2/87636874374.pdfIn PDF document text
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609ba0549554e---dinamenebopenub.pdfIn PDF document text
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/ojssrcjf8bqnmshsetdj9gr5p4/xuwijogig.pdfIn PDF document text
    • http://jjmcp.jp/userfiles/Image/file/beduvixesilive.pdfIn PDF document text
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0386e2a6dd---34960363930.pdfIn PDF document text
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/42160ef160b955669820482e11fd9460/41277623199.pdfIn PDF document text
    • http://watthaistuttgart.de/userfiles/file/10594639935.pdfIn PDF document text
    • https://epiphanych.com/images/file/20063484265.pdfIn PDF document text
    • https://cavalier-hundezucht.ch/userfiles/file/faxaterutasowokurimolit.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160b9a3569bbf7---wilajafegamifutukavilalem.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608446279c587---nogududopefifibunib.pdfIn PDF document text
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081a0927fdce---60175269176.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1878d41679---72028531170.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_off0000c2b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2B1 5424 bytes
SHA-256: 6c676c06ab6745e2c1d57a715a41181223097e16ac4395726ae6b0048806fd21
font_01_sfnt_off0000d522.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD522 10676 bytes
SHA-256: 9f517da4d82658d69f153932bf03c342996f70a5e0d408b15320642718bb23bc