Malicious PDF — malware analysis report

Static analysis result for SHA-256 86871a6aa94c8cc3…

MALICIOUS

PDF

68.8 KB Created: 2021-09-20 23:08:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c0b6f5ba5481edae0fadba5730d3562b SHA-1: f47f3a8bca168f5939e46f8de926afa93b5a04f4 SHA-256: 86871a6aa94c8cc32dd86a326f0e929b100590056da3f586b5604461a8163b34
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains an embedded JavaScript stream and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, forming a link farm. The primary function appears to be redirecting users to potentially malicious or phishing content hosted on these compromised or disposable domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://huntic.ru/uplcv?utm_term=tagalog+words+starting+with+c
    • https://castilloexterior.net/ckfinder/userfiles/files/83039680903.pdf
    • http://pololanna.com/user_img/files/luxedajedifi.pdf
    • http://kaitianjinghua.cn/admin/userfiles/file/202109051449131298.pdf
    • https://pmsp-me.com/userfiles/files/jemeguvigefaluzu.pdf
    • http://cuuhoatudong.com/upload/files/jovilatekesudumetot.pdf
    • http://circuitvietnamcambodge.com/hinhanh/file/godosawov.pdf
    • http://hotelclinton.it/userfiles/files/logekapolab.pdf
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/161467d3d7723b---sadizenofivovemigoni.pdf
    • http://konakelektrik.com/userfiles/file/ponosas.pdf
    • https://rubin2000-distribuitorshop.ro/userfiles/file/14929179599.pdf
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/1614251ff0dfa1---welovoruburexigebekonum.pdf
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/161411c5754d41---96241537769.pdf
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/f3733818476b0ac373820343a104d1fe/nexedekijugodudagogado.pdf
    • http://mis.nrru.ac.th/gradjournal/ckfinder/userfiles/files/tubexinovekuxigikilatu.pdf
    • http://bctlorraine.org/userfiles/file/5156012162.pdf
    • http://www.thegrcinstitute.org/app/webroot/js/ckfinder/userfiles/files/fagubisalan.pdf
    • http://coytex.net/ckfinder/userfiles/files/pezema.pdf
    • http://globomax.eu/userfiles/file/95533712897.pdf
    • https://baoyi-chuck.com/ckfinder/userfiles/files/37127938635.pdf
    • http://www.ntweac.edu.hk/admin/ckfinder/userfiles/files/sivatuxosexizafitixefobi.pdf
    • https://cristalparkhotel.com.ve/ckfinder/userfiles/files/rarupov.pdf
    • http://tano-cable.com/d/files/zekoganenimolasadobajup.pdf
    • http://xn--80aer5aza.xn--c1acndkmcarx.xn--p1ai/ckfinder/userfiles/files/65383621851.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b273.bin
2622bfdac17154a361ef095580b7322b96414b555bec445384e582321477150d
pdf-font-stream PDF embedded font (sfnt) at offset 0xB273 14112 bytes
font_01_sfnt_off0000d570.bin
4726431336f18cd5d3e9687b9a94b19316a1ef04e29c66773a5ac3b574cb9bdf
pdf-font-stream PDF embedded font (sfnt) at offset 0xD570 10568 bytes
font_02_sfnt_off0000ed53.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xED53 16792 bytes