Malicious PDF — malware analysis report

Static analysis result for SHA-256 6cf4b81fae9bd5f9…

MALICIOUS

PDF

84.5 KB Created: 2021-09-14 05:52:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: d50fb65fd1e17e99eb330bcef8e40007 SHA-1: 0815e9e2c4b888ee1b457f907ac72ae4850b740a SHA-256: 6cf4b81fae9bd5f92a56b58069411ba796e7bc7e76378022594d177881633f76
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple disposable hosting sites, a common tactic for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were directly extracted, the PDF structure and heuristic firings suggest it's designed to redirect users to external resources, likely for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://grupahatak.pl/admin/_fck_files/file/goketekuxet.pdf In PDF document text
    • https://thaibamboorestaurant.ca/phpsites/bard_ford/uploads/file/26213895723.pdfIn PDF document text
    • http://hbtsap.com/Upfiles/news/file///joforufexunejerugoxep.pdfIn PDF document text
    • http://preciz.com/uploads/wysiwyg/files/kevidatezutesorejizexuri.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/161381c63b2205---xuguxovirazife.pdfIn PDF document text
    • http://musorcentrum.around.hu/files/article/file/nidepudilupub.pdfIn PDF document text
    • http://clear-es.net/yamituki-n/uploads/files/9461347423.pdfIn PDF document text
    • http://historia-bfured.hu/userfiles/file/notuwixizu.pdfIn PDF document text
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/3fh2rc1gluvksd9sgptak45oj5/mutenesopo.pdfIn PDF document text
    • http://abwcockeysville.com/uploads/files/84777405346.pdfIn PDF document text
    • https://ekoelprom.pl/public/images/editor/file/lepufumesanutinupejemo.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/16137da3c58022---padivatapi.pdfIn PDF document text
    • https://rumahbaruku.com/contents/files/60953813762.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16130ea890762c---komasemezubanaxivixomes.pdfIn PDF document text
    • http://scbczy.cn/up_files/file/20210909_031424.pdfIn PDF document text
    • https://yumasri.com/assets/ckfinder/userfiles/files/12406082348.pdfIn PDF document text
    • https://ski-valloire.com/ckfinder/userfiles/files/lusaden.pdfIn PDF document text
    • http://megatex-plast.ru/pub/file/8675719384.pdfIn PDF document text
    • http://princeworldwide.com/multimedia/userfiles/file/purarex.pdfIn PDF document text
    • http://vincityhomes.vn/wp-content/plugins/super-forms/uploads/php/files/l236muqcphjoicca459st1ual6/duxonova.pdfIn PDF document text
    • http://maryalo.com/userData/board/file/nuvupewewe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=windows+7+home+basic+iso+file+downloadPDF 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_off0000e752.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE752 16940 bytes
SHA-256: ad882e0b4ee627e75f32d7966f4e964ab9083e9a4cbcf0aea9b79379482a704a
font_01_sfnt_off00011345.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11345 10812 bytes
SHA-256: cbbf53476d631f1a22ef70be2c83d0ca952c34b5ac48713f8a9e0d0b63e4eaba
font_02_sfnt_off00012c14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C14 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1