Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c9f803fe1a533af…

MALICIOUS

PDF

76.6 KB Created: 2021-09-09 15:03:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 3210d3bec39e93d8c09693f33e2d3d92 SHA-1: 4af4d82165c662593e49ff1d02bd2893ff575010 SHA-256: 4c9f803fe1a533af3ccd3ee066015cdfa92a8d6ea7f740b52dcd15fb546fefb3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous external links, many pointing to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://chcial.ru/uplcv?utm_term=season+5+boku+no+hero+academia PDF link annotation
    • http://tpokebar.com/uploads/files/98341734623.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/101de83d104deae2a958a8483c8a12f3/22719583101.pdfIn PDF document text
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/161364e468a285---wedolaniwazilopexometinig.pdfIn PDF document text
    • http://bursaceyizgelinlik.com/images_upload/files/xilufomusu.pdfIn PDF document text
    • http://nkmate.com/FileData/ckfinder/files/20210905_054A26F847B36CB6.pdfIn PDF document text
    • http://udokutscher.de/gfx/userfiles/files/dujasubadajaxonetekef.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/3abed09564680c3276a91bf7f68ac4d9/69067884978.pdfIn PDF document text
    • http://siamsankyo.com/Uploads/file/2188513239.pdfIn PDF document text
    • https://pcparts.fr/ckfinder/userfiles/files/niwijopupumivefosim.pdfIn PDF document text
    • https://monyetmesum.com/contents/files/fepowovakite.pdfIn PDF document text
    • http://aytekinpolatel.com/image/files/riwibobim.pdfIn PDF document text
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139866b8a526---64143875667.pdfIn PDF document text
    • https://fotojursa.cz/userfiles/file/22735584001.pdfIn PDF document text
    • http://juditphotography.com/picture/userfiles/file/27103219941.pdfIn PDF document text
    • http://4yoga.by/pics/files/13758593830.pdfIn PDF document text
    • http://ski-experience-japan.com/images/blog/file/takufaweniwebakez.pdfIn PDF document text
    • http://biondiairsystem.it/userfiles/files/76490991796.pdfIn PDF document text
    • http://www.radanhorse.com/resource/files/91857344302.pdfIn PDF document text
    • http://mispuntossaga.com/campannas/file/80976248925.pdfIn PDF document text
    • https://samuelben-horin.com/userfiles/file/72672506709.pdfIn PDF document text
    • http://schubert-hh.de/image/file/wumavadobakip.pdfIn PDF document text
    • https://jecoexports.com/ckfinder/userfiles/files/70270010874.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_off0000c531.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC531 11032 bytes
SHA-256: dd019c13899e626c528fa63467d6c140e87af0e7b6011832c20cf90989f22cf9
font_01_sfnt_off0000deab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEAB 18028 bytes
SHA-256: 43a0a8d6b4aff27cd94455d6edfd138f42f4e33a45a3b328d0616350f793250d
font_02_sfnt_off00010ca3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CA3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1