Malicious PDF — malware analysis report

Static analysis result for SHA-256 b30c15661db7eac0…

MALICIOUS

PDF

82.7 KB Created: 2021-08-25 10:02:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f84998452582a48eca4497fb154c8d2f SHA-1: 8a57b9120adf0fa4c5fea197610ba2539d24c9ab SHA-256: b30c15661db7eac0c08edbe27675efbe9c03df8db0b1502d943d04f39a314f4a
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised CMS upload storage or are part of a link farm hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the structure and URL patterns suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://cructi.ru/uplcv?utm_term=ruby+check+if+string+in+array PDF link annotation
    • http://bjhtdszdh.com/v15/Upload/file/2021517057194235.pdfIn PDF document text
    • http://adbuilder.at/ckfinder/userfiles/files/xovutakilazolaxenasizema.pdfIn PDF document text
    • http://findmealocalpainter.com/insurazon/admin/userfiles/file/76212993671.pdfIn PDF document text
    • http://tygodnikzuzlowy.pl/ckfinder/userfiles/files/7868812570.pdfIn PDF document text
    • https://perfectsextherapy.com/public_html/userfiles/file/70808907582.pdfIn PDF document text
    • http://sentezetutmerkezi.com/upload/ckfinder/files/munefod.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16091211c5a0d7---wekab.pdfIn PDF document text
    • http://lexen.ca/userfiles/files/jomakaxuzo.pdfIn PDF document text
    • http://geofer.eu/userfiles/files/bupozorinuvubasutup.pdfIn PDF document text
    • http://trenermichal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1609092b070fa6---4481372978.pdfIn PDF document text
    • http://windmill-bv.com/userfiles/files/2034181427.pdfIn PDF document text
    • http://etenindex.nl/images/uploads/72607625409.pdfIn PDF document text
    • http://akicgiyim.com/userfiles/file/49744658075.pdfIn PDF document text
    • https://manorhair.com/uploads//files/202108091702081713.pdfIn PDF document text
    • https://toptenstudy.com/upload/files/BodyFile__611114AF32825.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607e2a4c9a433---17870378272.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609a138369514---tulesamubu.pdfIn PDF document text
    • https://telewebmarketing.com/FCKeditor/file/zagerew.pdfIn PDF document text
    • https://ecomassage.pt/wp-content/plugins/super-forms/uploads/php/files/airk66q35bac7r3sfhppkuh5ti/74685648292.pdfIn PDF document text
    • http://tonystelly.com/clients/873487/File/62519830081.pdfIn PDF document text
    • http://jngf.cn/files/file/63515429106.pdfIn PDF document text
    • https://gkatsov.com/userfiles/file/23094812038.pdfIn PDF document text
    • http://shangrilayunnan.com/ckfinder/userfiles/files/48626813318.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_off0000daed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAED 10940 bytes
SHA-256: c13446f51b62aa7181eb008323c0f808dd522ef29feb73b5c02de1a0dadc7fee
font_01_sfnt_off0000f44f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF44F 17896 bytes
SHA-256: ee670e5efa4834bcb49f7d1b40532791015f79ee2df8f9e248ccaa6af7c7e49c
font_02_sfnt_off000123f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123F7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1