Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8403f9f51f16026…

MALICIOUS

PDF

71.4 KB Created: 2021-09-04 08:09:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: d72d405a628a0d3593cdfa930c9a6cde SHA-1: e279d5c221ebd85fbad9052003183d6bacf19042 SHA-256: a8403f9f51f1602678a108dd6fafe36e55c2da67d858db4698fa74d7c92a1b3d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on disposable domains or compromised CMS uploads, suggesting a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are consistent with a malicious PDF dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://geteffective.biz/uploadfiles/file/56577429877.pdf In PDF document text
    • https://lesartsdansmonjardin.com/userfiles/file/20210601025207.pdfIn PDF document text
    • http://tc-antey.ru/uploads/files/10541578477.pdfIn PDF document text
    • http://gorsilawfirm.com/userfiles/file/4068451413.pdfIn PDF document text
    • https://gionggiacam.gagiongvitgiong.com/ckfinder/userfiles/files/guromoxoner.pdfIn PDF document text
    • http://wmhsclassof1977.com/clients/34196/File/39511570690.pdfIn PDF document text
    • http://immobilieninvestors.eu/userfiles/file/fapotapefuponuvakisavuxit.pdfIn PDF document text
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/frmnombe6t9d4ggh769d9ithg6/28989893607.pdfIn PDF document text
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/a2b8dda6d8e5c9940b9a5d10f053f33e/96216383162.pdfIn PDF document text
    • http://combatkuntao.com/ckeditor/ckfinder/userfiles/files/80277586704.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/gtrf51q7oeotdq3egh5mh6b9ae/60601087934.pdfIn PDF document text
    • http://aj-logistics.com/stock/userfiles/file/29682424742.pdfIn PDF document text
    • http://vce34.ru/attachments/file/zusijerozef.pdfIn PDF document text
    • https://dienlanhbachkhoa.info/upload/files/lujuxusibu.pdfIn PDF document text
    • http://maasmartcity.com/userfiles/file/96829437875.pdfIn PDF document text
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/16126871c30c60---6730471999.pdfIn PDF document text
    • https://www.ergunaygoren.com/wp-content/plugins/formcraft/file-upload/server/content/files/160802faad8c16---bovemena.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606c690adf826---vugorenizojosekigu.pdfIn PDF document text
    • https://xlspandoek.nl/userfiles/file/83253523627.pdfIn PDF document text
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e2b50a90fb---lizefifevexirot.pdfIn PDF document text
    • http://webmba.fr/client/logo/file/wekigisijeko.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=pension+fund+management+pdfPDF 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_off0000b726.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB726 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cf3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF3D 10796 bytes
SHA-256: f96e48de101506b4d7deb7fef99ecf99a62f6568b70a9fa99bf622ca374e0d7d
font_02_sfnt_off0000e7ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7EF 16084 bytes
SHA-256: c14a5072b17be491d37382b14f3710f0c8ff01a148c26c78f3f9507ec1a5ec46