Malicious PDF — malware analysis report

Static analysis result for SHA-256 65cbc23b6ac658d7…

MALICIOUS

PDF

81.2 KB Created: 2021-09-23 14:14:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: cd6115527529c301c96ba633982092ef SHA-1: f805d17e1c6613f7f316d9de40689f451eb64149 SHA-256: 65cbc23b6ac658d729d81fd7eeaf2926f0f9a4b04a0f7712f5506be883528f44
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and URL patterns suggest it's designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://goodnest.info/tctt/sites/aaa/file/99431825197.pdf
    • https://ingatlanfelugyelet.hu/uploads/file/53631520015.pdf
    • https://evrenmentese.com/upload/ckfinder/files/3431654519.pdf
    • http://scard.vn/app/webroot/uploads/files/36290223597.pdf
    • http://www.css-jp.com/upfile/files/2021/09/06/14510274913.pdf
    • https://mmtours.si/uploads/vusosavevodotoma.pdf
    • http://daehwa.info/uploaded/file/11156616724.pdf
    • http://artgrafika.cz/userfiles/file/rowiwatemiwoziziwugimafub.pdf
    • https://bravo-hk.com/userfiles/file/77480816905.pdf
    • http://mamtaniketan.com/userfiles/file/garigezopufedojugunuxex.pdf
    • https://editora-arara-azul.com.br/site/admin/ckfinder/userfiles/files/kemaforovivixujezuvefozab.pdf
    • https://bela.geekers.tw/upload/file_folder/file/5775371652.pdf
    • http://uforoi.com/app/webroot/uploads/files/2591671628.pdf
    • http://pusheng168.com/uploadfiles/20210902201657.pdf
    • https://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146633424ea3---febuserajase.pdf
    • https://mr-alian.com/upload/ckfinder/files/kofovida.pdf
    • http://julianina.dk/upload/file/77497992078.pdf
    • http://fge-service.com/userfiles/file/61770931985.pdf
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/161371abef20f2---lilunitekekutukegexok.pdf
    • http://oletrans.sk/editor_uploads/files/dawozizelelijozilupimoxu.pdf
    • https://feng-shuiworld.com/userfiles/file/74181664928.pdf
    • https://minhvuongthuphap.com/upload/ck/files/96441400665.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=how+to+global+rom+redmi+7a
    • 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_off0000d79d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD79D 16792 bytes
font_01_sfnt_off0000efb4.bin
1965a3e688f7b0bf39831f79b3bb41767e9b251d0708a994ae33d4cb19ae9cbc
pdf-font-stream PDF embedded font (sfnt) at offset 0xEFB4 10588 bytes
font_02_sfnt_off000107be.bin
97dd458bf03cb047188320032d3d269ebef5a1943c627c8703ab621af6821757
pdf-font-stream PDF embedded font (sfnt) at offset 0x107BE 18356 bytes