Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8c88b6de4bc9606…

MALICIOUS

PDF

81.6 KB Created: 2021-09-23 20:04:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 112dd0e7bb9c530ec591d7e02cb663c1 SHA-1: e32d27cd35acd54961cef28ac62bf197027ef7aa SHA-256: c8c88b6de4bc9606b6232c5dda8a9f142c07df5e52fca6cd9b829ed497773452
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed for malicious redirection. ClamAV detection and ML classification strongly suggest malicious intent, likely for phishing or malware delivery. Although no scripts were explicitly extracted, the structure and URL patterns are consistent with a malicious PDF dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://synerhu.ru/uplcv?utm_term=kotor+character+creation+guide PDF link annotation
    • https://luxartparquet.com/wp-content/plugins/super-forms/uploads/php/files/81ef80b847976e55398cab101e7d7e8e/furazowagebafumunimotuxi.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/a77177438cc831386ce06886e856e1e7/rifabakilugajade.pdfIn PDF document text
    • https://maurinet.com/userfiles/file/toxavoneladimaroga.pdfIn PDF document text
    • http://dambi.pl/userfiles/file/10290651859.pdfIn PDF document text
    • http://gzky.cn/dubeite/ckfinder/userfiles/files/20210906_015342.pdfIn PDF document text
    • http://kwong-cheong.com/userfiles/kupuwiba.pdfIn PDF document text
    • http://livilgirls.com/files/ganefagekanaxovuj.pdfIn PDF document text
    • http://maychebiengoduykhuong.com/media/ftp/file/duwapoxawosobul.pdfIn PDF document text
    • http://xn----7sbndn5at.xn--p1ai/uploads/files/63603678898.pdfIn PDF document text
    • http://kino-cosmik.ru/sadm_files/87837787834.pdfIn PDF document text
    • https://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/161315effac24a---ragokebalu.pdfIn PDF document text
    • http://ajej.pretty-match.com/upload/files/24333445725.pdfIn PDF document text
    • http://agilesolutions.in/uploads/xebozumag.pdfIn PDF document text
    • https://textolinguisticsolutions.com/upload/editor/file/tekosuxirumo.pdfIn PDF document text
    • http://clingac.com/d/files/rezezanupapo.pdfIn PDF document text
    • http://ovecollection.com/royal/admin/images/products/file/32183628466.pdfIn PDF document text
    • http://jocoseatee.com/userfiles/files/60078232666.pdfIn PDF document text
    • http://srilakshmienterprises.net/uploads/33063291846.pdfIn PDF document text
    • https://www.loscam.com/lib_common/ckeditor/ckfinder/userfiles/files/57266527639.pdfIn PDF document text
    • http://curry-box-deluxe.de/userfiles/file/bipalanafulibenanufojulo.pdfIn PDF document text
    • http://ajarnveerapong.com/UserFiles/file/kepadukowenurabiwitujidig.pdfIn PDF document text
    • http://machinesupplier.cn/data/product/file/2021913_224938_940.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_off0000db06.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB06 10524 bytes
SHA-256: 4e28f0641caf3fcdc6ea9bbfbef111546a09a38696d880252f7d5ef71b23b1e5
font_01_sfnt_off0000f2b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2B7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010ac9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AC9 17624 bytes
SHA-256: 855cae1c7285ef5b65f2025d43d13a1b16a4900210c3d30349b47c2738d79608