Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b43731261072fb0…

MALICIOUS

PDF

69.1 KB Created: 2021-09-06 17:09:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 3a478f898eb9d77eccb19c0d0300fab9 SHA-1: c8c2f63234b21feec7e1156f6eda682d39a1986a SHA-256: 2b43731261072fb0c4c0bd0ece34e8fb65291b822cd45b9055a5d246e83c555c
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to other PDF files hosted on various domains. Several heuristics indicate this is a link farm, with some links pointing to compromised CMS upload storage. ClamAV detected this file as 'Pdf.Phishing.Trojan', suggesting a malicious intent behind the link farm, likely to distribute further malware or phishing content. No scripts were extracted, and the document body was unreadable.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • 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.
  • 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://stepweystudy.com/ckfinder/userfiles/files/josavasabizedudimudokasuk.pdf In PDF document text
    • http://phuquytravel.com/nguyenvanlinh/files/worazipoz.pdfIn PDF document text
    • http://shqinze.net/admin/upimg/file///46506716970.pdfIn PDF document text
    • http://creativeindustries.ru/uploads/userfiles/file/vefelapula.pdfIn PDF document text
    • https://skyzoan.com/cake/beta/userfiles/file/64073449110.pdfIn PDF document text
    • https://infypos.com/infyposcms/media/xovudebejumewev.pdfIn PDF document text
    • http://gorsilawfirm.com/userfiles/file/xobibifarotuga.pdfIn PDF document text
    • http://tatugigo.com/ckfinder/userfiles/files/tumumi.pdfIn PDF document text
    • http://pc75.net/upfiles/file/1623165204.pdfIn PDF document text
    • http://www.siphonicflowmandiri.com/upload/files/pavibunovikife.pdfIn PDF document text
    • http://smolninskayahotel.com/userfiles/file/nasereporape.pdfIn PDF document text
    • https://sindonis.com/userfiles/file/37424200885.pdfIn PDF document text
    • http://master-sign.ru/ckfinder/userfiles/files/73770995154.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16083ad8b111ed---dekegu.pdfIn PDF document text
    • http://studiodabo.eu/userfiles/files/xelasujupigumomug.pdfIn PDF document text
    • https://socialchangefactory.org/wp-content/plugins/super-forms/uploads/php/files/21d7f0c9012fd567e8d034697861d02b/66174974422.pdfIn PDF document text
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607f5e50385ba---gapem.pdfIn PDF document text
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/95e5fccjht9rp3cho0gei9g37f/44945137373.pdfIn PDF document text
    • https://vivekanandbawwa.com/userfiles/file/lavenixuxabuwuzinejoxatuz.pdfIn PDF document text
    • https://www.albispanaderia.com/wp-content/plugins/super-forms/uploads/php/files/350a96ddd91e580b9cf860d8f23fabe7/xonaxejebilitiba.pdfIn PDF document text
    • http://lycee-elm.info/userfiles/file/38806987829.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160dfc648333b3---30156871186.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/1607ff22be0188---66603879886.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=zip+to+pdf+converter+free+download+for+androidPDF 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_off0000b236.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB236 10560 bytes
SHA-256: f93454faf6e1703b6909c39c1ee4c6b863130ddc2b219ef8325fcf03f178d933
font_01_sfnt_off0000ca7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA7C 14264 bytes
SHA-256: 523caa26f39aa11132200c08ed18eb51a289c945284b9ee321660d8ff735db92
font_02_sfnt_off0000eddf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDDF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1