Malicious PDF — malware analysis report

Static analysis result for SHA-256 c661a2d4a281cf85…

MALICIOUS

PDF

67.9 KB Created: 2021-06-23 00:29:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: c58a2dd2aa7507f05a862d373f4a3863 SHA-1: 82c0380ef24b69d75bcfa1caa965d4edc527f55e SHA-256: c661a2d4a281cf8548dfc48417c6f19105f17188dfc5a6771087c4f343cec0f7
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. The file's structure and embedded URLs align with techniques used to host and distribute malicious payloads.

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://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077ad5830c2f---gogepumafuxota.pdf In PDF document text
    • https://e-lightingcontrols.com/wp-content/plugins/super-forms/uploads/php/files/cc15843f0e58aa2cfdb59a3f5d3ae4f2/56655013333.pdfIn PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cdff06eecc---kutoniwagela.pdfIn PDF document text
    • http://codemessaging.net/ckfinder/userfiles/files/51219118754.pdfIn PDF document text
    • http://easyreturn.store/userfiles/file/27496800522.pdfIn PDF document text
    • http://garantc.ru/userfiles/file/genoxu.pdfIn PDF document text
    • https://elektrona.cz/files/file/17372395054.pdfIn PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607150379acc2---veluzij.pdfIn PDF document text
    • https://aftaplan.com/works/peepsparty/html/upload_files/file/93494652999.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/2d301b301822ac7cc17a027b39496950/pininaxelenarofinod.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1607359be50f77---renidejaxuxul.pdfIn PDF document text
    • https://a2designbg.com/userfiles/file/mulefapomufuxawikagem.pdfIn PDF document text
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/imdgiif2rtda1faqnaiib4fqf1/90448586403.pdfIn PDF document text
    • http://denis-lefebvre-services.com/fichiers/file/wosoxowezubexumof.pdfIn PDF document text
    • http://bamt.be/wp-content/plugins/formcraft/file-upload/server/content/files/160946ebe6814a---zijepaxejexomusoke.pdfIn PDF document text
    • http://brandiassociati.it/userfiles/file/17953246177.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=100+kb+size+converter+pdfPDF link annotation
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c1de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1DE 5320 bytes
SHA-256: c2f8f388522439cdfff7b26ca9a6714635cc474f2b57ecd350129cc028105d5b
font_01_sfnt_off0000d40f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD40F 1800 bytes
SHA-256: a36eee06fef6ce219692c4ec918276ac99413e4fd1e3666e4031624f9289d620
font_02_sfnt_off0000dc9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC9C 11192 bytes
SHA-256: 8a744f74a0d9dc1f73e02e119cbff384f62c6e0aad8c91876ab05767885d6961