Malicious PDF — malware analysis report

Static analysis result for SHA-256 cef9375eb86c90b5…

MALICIOUS

PDF

88.8 KB Created: 2021-09-21 00:17:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 87ed6d9cb3de34c11f336df7bf657852 SHA-1: 482736603462cbbb61b9c0a14e0b6581f9997c24 SHA-256: cef9375eb86c90b5a6c950fb2ba9a8ea325dbd3f0fa8215216103935b867235e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable hosting and appear to be part of a link farm designed to redirect users. The `wkhtmltopdf` authoring application suggests it may have been generated as part of a malicious campaign. No scripts were extracted, but the high number of suspicious URLs indicates a strong intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://synerhu.ru/uplcv?utm_term=games+under+1gb+for+android PDF link annotation
    • https://conexusinternational.com/ckfinder/userfiles/file/kosumuzagalezizulujefupa.pdfIn PDF document text
    • http://kammatrans.com/userfiles/files/faxekonoxixamaputivu.pdfIn PDF document text
    • http://thegioimaychaybo.com/app/webroot/uploads/files/255037355.pdfIn PDF document text
    • http://qianxish.com/ckfind_image/files/fovapob.pdfIn PDF document text
    • http://solarissoft.com/img/userfiles/files/sujazosazenapexaw.pdfIn PDF document text
    • http://alarm.pl/userfiles/file/49401011125.pdfIn PDF document text
    • http://saharun.org/uploads/ckfinder/userfiles/files/wijixawude.pdfIn PDF document text
    • https://nguyenhungstone.com/uploads/image/files/zalomuw.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16144256cecbc5---jubiwapezafemo.pdfIn PDF document text
    • https://familienbilstrup.dk/ckfinder/userfiles/files/lositodugan.pdfIn PDF document text
    • http://baaningdoi.com/file_media/file_image/file/domebegufazulimi.pdfIn PDF document text
    • http://kustari.net/userfiles/file/falufoketinamage.pdfIn PDF document text
    • http://filtrydokoparek.pl/img/all/niguvoximolijiv.pdfIn PDF document text
    • https://drbumbnursinghome.in/ckfinder/userfiles/files/bijisovaso.pdfIn PDF document text
    • http://elisa5888.com/shopadmin/upload/files/95893671663.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/9166784212.pdfIn PDF document text
    • http://hophungvietnam.com/app/webroot/uploads/files/biwotur.pdfIn PDF document text
    • https://matraci.info/UserFiles/File/zovikisugewinurivipigi.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613c46f6dd324---desirebatumaperekep.pdfIn PDF document text
    • http://eugensa.lt/app/webroot/uploads/userfiles/files/36991038662.pdfIn PDF document text
    • http://yesfabric.com/images/upload/File/wowim.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_off0000f664.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF664 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010e7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E7B 10884 bytes
SHA-256: c22d1b120b0d3d3f2aa29ecf621383be03e6a26d9571f3de304ca4c3123abf53
font_02_sfnt_off0001276e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1276E 17964 bytes
SHA-256: ff7d80c84ee754e530c5d8ced22f23f2eec25bac6d2abfd1a5bb1a8f4205e836

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