Malicious PDF — malware analysis report

Static analysis result for SHA-256 e97792459ab0774d…

MALICIOUS

PDF

78.4 KB Created: 2021-06-08 12:08:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-27
MD5: 1f23e19709d9d25ba58ca897f97224be SHA-1: 50eb7ded5686da89f2ed5879b66046191b99e0e6 SHA-256: e97792459ab0774dcefd4c184fb23d7cc2a324ec902aa6ab9fe3dc8b5315335b
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains numerous external URLs, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm for SEO manipulation or phishing. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and a date, indicating it was likely generated programmatically to host these links.

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://chcial.ru/uplcv?utm_term=fighting+games+unblocked+at+school PDF link annotation
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/cvq6b6tt3p5c9f5ijd4v295s49/3617319096.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/160a539b9b59ba---wetajisimuvopawaxebotafiv.pdfIn PDF document text
    • http://tecsun-moscow.ru/docs/file/93332688527.pdfIn PDF document text
    • http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/j67tl8vugoi7kt46bpoaspl7s3/liwub.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/845cof1ej9pmrff2i0a2igl5u6/dojaxoju.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/0e4abb65ee3ef5ae5790efa64c899ccb/16741080783.pdfIn PDF document text
    • http://cy2hand.com/userfiles/xiturilikolipakexesikox.pdfIn PDF document text
    • http://domplus.su/userfiles/files/sivipuvuku.pdfIn PDF document text
    • http://sklepjola.pl/userfiles/file/vabulelisezodanagutanona.pdfIn PDF document text
    • https://www.bakirkoytemsilcisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160855f3150c51---nozesulekosokuzasedoto.pdfIn PDF document text
    • https://mmagame.com/userfiles/file/zazakuzojodaterugig.pdfIn PDF document text
    • https://travelstore.tn/userfiles/file/nunofigoxi.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a1a532d4018---pixuk.pdfIn PDF document text
    • http://kolesnikov.pro/ckfinder/userfiles/files/dufixalegusebozosa.pdfIn PDF document text
    • https://afayl.com/userfiles/file/77440438029.pdfIn PDF document text
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a573df40f32---32649327325.pdfIn PDF document text
    • http://beetsom.com/PROGRAM_FCKeditor_UserFiles/file/102093866760a7c786a2f03.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_off0000f4ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4ED 5416 bytes
SHA-256: c8df6aa913d727df52be8cf0ccab0fd308fdb1ea37ee2cb4092037bb77bfa3df
font_01_sfnt_off00010739.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10739 10420 bytes
SHA-256: 76c365b147d601dd0ac78b57de798a16659cfbd166588b1e746a8c5d9218d082