Malicious PDF — malware analysis report

Static analysis result for SHA-256 cff8bdd601fbef6e…

MALICIOUS

PDF

70.4 KB Created: 2021-10-02 23:01:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 42391e14ba5955b7612f9c7a3e2fcb53 SHA-1: d463b2db48d5b0327706912255874fc7827ce149 SHA-256: cff8bdd601fbef6e5704a4df6748d46e8cebd45bc2d7f0f212a5ccb047008f4a
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to numerous other PDF files hosted on various domains. The presence of multiple external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly suggest a campaign to manipulate search engine results or distribute further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://hoavily.com/uploads/files/vesugusunofipejo.pdf In PDF document text
    • http://reversetheclocknow.com/ckfinder/userfiles/files/67730944535.pdfIn PDF document text
    • https://riondene.ch/img/uploads/file/vopizelap.pdfIn PDF document text
    • http://szolnokepul.hu/userfiles/file/83108801089.pdfIn PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-29/20210929152206926786.pdfIn PDF document text
    • https://heart-calligraphy.com/uploads/files/202109282306061459.pdfIn PDF document text
    • http://news-hk.net/uploadfile/file///2628702084.pdfIn PDF document text
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16133d8a0949fb---11742656322.pdfIn PDF document text
    • https://alarouba.com/ckfinder/userfiles/files/2748293541.pdfIn PDF document text
    • https://vadihosting.com/calisma2/files/uploads/66319122204.pdfIn PDF document text
    • https://e-casainteligenta.ro/userfiles/file/vobetosebifepowegodobil.pdfIn PDF document text
    • http://chiangmaicharmingtravel.com/ckfinder/userfiles/files/72968718447.pdfIn PDF document text
    • http://mackits.eu/image/lefupixexoletagupi.pdfIn PDF document text
    • http://hermanosgolbano.com/admin/fckeditor/editor/filemanager/connectors/phpfile/nagevamu.pdfIn PDF document text
    • http://ballarioarchitetti.eu/userfiles/files/gujajem.pdfIn PDF document text
    • https://heart-calligraphy.com/uploads/files/202109271849128016.pdfIn PDF document text
    • https://xebecdesign.com/xebec/userfiles/file/71489748595.pdfIn PDF document text
    • http://gesundimjob.at/images/content/files/fowuwed.pdfIn PDF document text
    • https://happycondo.leaddeehub.com/userfiles/files/82857978459.pdfIn PDF document text
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/dc704269964e734048ddaa83c21e437f/rakukeweromuwejasovuxezo.pdfIn PDF document text
    • https://www.sexualaufklaerung-schule.ch/ck/ckfinder/userfiles/files/96861480615.pdfIn PDF document text
    • https://listocrm.com/userfiles/files/47548488619.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=monster%27s+ball+parents+guidePDF 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://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_off0000b14c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB14C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c95e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC95E 15840 bytes
SHA-256: cf9c3d186d80d20e70c857e3d1839740931e13393e91903fdce9b38d144f4c80
font_02_sfnt_off0000f190.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF190 10836 bytes
SHA-256: ef0a4a1d141925d25fc641860c8edc662f0282dca11724a7813907bf0c69f8f8