Malicious PDF — malware analysis report

Static analysis result for SHA-256 42edcbfc38e879eb…

MALICIOUS

PDF

87.1 KB Created: 2021-09-18 08:07:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 1d1f1bfa6e18de8c1d05261f5bc066dc SHA-1: 66de485aa71b2e28cf14fa2d23366d4b7a60b931 SHA-256: 42edcbfc38e879eb18b8d0e79e31758c6772d8f4c450d7e246b5799b9c463c0d
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which are part of a link farm hosted on disposable or compromised domains. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution via these links. The embedded JavaScript may be used to further obfuscate the malicious activity or exploit PDF vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://catamma.ru/uplcv?utm_term=best+light+android+emulator PDF link annotation
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135c38981202---85608909479.pdfIn PDF document text
    • http://geologicatoscana.eu/userfiles/files/59532763001.pdfIn PDF document text
    • https://thietbixaydungcantho.com/canthomobile2/public/images/sanpham/files/sejare.pdfIn PDF document text
    • http://rosg.net/sa_upload/userfiles/file/20210914083057.pdfIn PDF document text
    • http://tencanpowder.com/d/files/sulilemabe.pdfIn PDF document text
    • https://testgit.begurholidays.com/uploads/userfiles/files/26214203689.pdfIn PDF document text
    • http://sivam.pl/files/file/83167473647.pdfIn PDF document text
    • https://fpcofmacon.com/nbloom/fckuploads/file/wodivokubotedizidutewa.pdfIn PDF document text
    • http://hwayoung.kr/upfile/files/nazowizoserutowopepibiwo.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/161390540cba2f---jidomutosemomiranoxuro.pdfIn PDF document text
    • https://www.rongoldmanlaw.com/system/js/back/ckfinder/userfiles/files/70930494929.pdfIn PDF document text
    • https://value.ae/userfiles/file/nuxewolitatol.pdfIn PDF document text
    • http://wxhsbl.com/ckfinder/userfiles/files/20210903_014654.pdfIn PDF document text
    • http://vizugy.hu/uploads/files/27062534177.pdfIn PDF document text
    • https://studiecarriere.it/uploads/file/sefogasafaboma.pdfIn PDF document text
    • https://shoppingplanet.cityplanet.ro/ckfinder/userfiles/files/58454337733.pdfIn PDF document text
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/d8071dbc315c22cead57efcc45ce2756/salexazux.pdfIn PDF document text
    • http://fongyoskert.hu/userfiles/files/36585694800.pdfIn 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f112.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF112 10848 bytes
SHA-256: bf99d614d9c88b5e675e3362bd9205bb8d97a6338b98d0940c74078ca259e476
font_01_sfnt_off000109b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109B7 17536 bytes
SHA-256: 7d45d4965cc00e8424e956f384cb4da87046fc374297bc957defe122d4c3aea6
font_02_sfnt_off000136e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136E0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1