Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f90b87dbb126c8a…

MALICIOUS

PDF

80.3 KB Created: 2021-09-18 17:04:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 2dc5f137fc99117084cac1cbdc096b3e SHA-1: a09841faead147621d6eb0c21206dbc05381a041 SHA-256: 3f90b87dbb126c8a528bf080593f029010571c5fbdd3ea9bd7af880f6f06738e
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous external PDF files hosted on compromised CMS platforms. The ML classifier strongly indicated maliciousness, and the heuristics suggest the document is designed to lead users to potentially malicious content. No scripts were extracted, limiting the ability to determine specific execution methods beyond the initial document delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9967

Heuristics 5

  • 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://www.3dreamchurch.com/wp-content/plugins/super-forms/uploads/php/files/2453c90dc6d84fa06a698fa6dc8f2e53/kusirorutezuritavuwilepas.pdf In PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614429b239879---78836898618.pdfIn PDF document text
    • http://finchamauto.com/pics/mejegox.pdfIn PDF document text
    • https://crossfitbeeshark.ro/app/webroot/files/userfiles/files/xetivubinotoxe.pdfIn PDF document text
    • http://hungthanhauto.com/luutru/files/69620355129.pdfIn PDF document text
    • https://millinerandassoc.com/files/file/59059284692.pdfIn PDF document text
    • http://dj-maily.com/uploads/pages/files/15722283417.pdfIn PDF document text
    • http://heatexchangersolution.com/upload_fck/file/2021-9-12/20210912215708742364.pdfIn PDF document text
    • http://www.samuitns.com/image/upload/File/29352299885.pdfIn PDF document text
    • http://gursakaryahukuk.com/images/file/winalijimutu.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/maroxesigilulekar.pdfIn PDF document text
    • http://pelejas.com/IMAGENS/CKFINDER/files/nelodizerojadovaduja.pdfIn PDF document text
    • https://zhansq.cn/upload/file/gepukazafa.pdfIn PDF document text
    • http://thrifthelp.com/flash/thrifthelp.com/file/nevagerufalasebezijonidal.pdfIn PDF document text
    • http://zs-oilfieldequip.ru/d/files/82529486583.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fad3d1fd81---mafirenifafupiza.pdfIn PDF document text
    • http://erbaytag.com/resimler/files/54609671484.pdfIn PDF document text
    • http://hbaoge.com/upload/files/54995482062.pdfIn PDF document text
    • https://renetravel.ro/images/files/59641384760.pdfIn PDF document text
    • http://ajitcoatings.com/uploads/26947614702.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/161341ded42e63---9920096797.pdfIn PDF document text
    • https://b2b-intelligence.it/uploads/file/galosirajad.pdfIn PDF document text
    • http://pcccmiennam.com/media/ftp/file/mopeposodujakegenarotona.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=channel+4+livePDF 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_off0000d846.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD846 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f05c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF05C 9892 bytes
SHA-256: 139d55269879b890949ef3aebb5e173265020b05b33a1bee714a1b3e2ef49102
font_02_sfnt_off00010611.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10611 18012 bytes
SHA-256: 40145605f51dcf33c350fec6513d42bbd12bd6e5ecad306e53a0c57306e82413