Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c28acc3fbb22980…

MALICIOUS

PDF

78.8 KB Created: 2021-06-12 21:11:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: 163de98800ac61a15544d52ad6ce4782 SHA-1: 10d36ad4f617988f2f0ceee5644374050085e895 SHA-256: 4c28acc3fbb22980d58c78592e0a6cfafe6ed19dafb82a5f426da2a32356b53d
156 Risk Score

Malware Insights

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

The PDF file contains numerous links to external websites, many of which are hosted on compromised WordPress installations, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. The embedded content, though heavily obfuscated, appears to be part of a lure to trick users into clicking on these links.

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://queure.ru/uplcv?utm_term=cocktail+full+movie+download+400mb PDF link annotation
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/fba419f2db96aeb207d9baf9a3d6d495/57928947712.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1f991ad61f---10361600020.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/6508284ce8aa9e515fc046b4085baf02/59716694060.pdfIn PDF document text
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ac3b2dd825---jazasisurivone.pdfIn PDF document text
    • http://sammyuriasproperties.com/userfiles/files/51264401992.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b05d570f672---58345944862.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a8c4d75dce2---32927347302.pdfIn PDF document text
    • http://ed-web.cz/userfilesfile/xesivajid.pdfIn PDF document text
    • http://martom24.pl/martom/userfiles/file/55810650934.pdfIn PDF document text
    • https://tecnicadovolante.com/images/file/xutodajaripuwo.pdfIn PDF document text
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/5c63c720cdfda28f8cb210c1f260876b/bewonevemiwafojuguke.pdfIn PDF document text
    • https://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160c1e23859456---75708287738.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/160829df8082d0---xefevewakik.pdfIn PDF document text
    • https://www.emmabowman.com/wp-content/plugins/super-forms/uploads/php/files/20961c8d0ce23b8db89dab5a6930afc7/fulosutewujepetidigug.pdfIn PDF document text
    • https://zemiigori.com/uploads/file/78387147376.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_off0000f17b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF17B 5384 bytes
SHA-256: 843296cfe982ea4d6b93aab4831b6052c38394086202893551650a2a4a62af1e
font_01_sfnt_off000103de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103DE 12688 bytes
SHA-256: 93eceab4674edeb8d6e8ef46281acd1ba024da50a7922c7fa5d82ff0fa06108b