Malicious PDF — malware analysis report

Static analysis result for SHA-256 312f41d136ecc655…

MALICIOUS

PDF

152.7 KB Created: 2021-07-15 16:41:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: b9c1938f5e169e0a342d0a9e18eb733d SHA-1: 1329ebb8f50c4ddb4464fd24de9ce7cbde58af0c SHA-256: 312f41d136ecc655f0fd34b17a30690062dc5dd6f2ad3471de2f3821c73deac0
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS upload directories and disposable hosting, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/ec020682ce4eed579d8f1c76711631ee/75291726666.pdf In PDF document text
    • http://atthaya.com/file_media/file_image/file/mipukipizaxunoku.pdfIn PDF document text
    • http://kursadowicz.pl/Upload/file/42031018468.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ceecdd4f93---49724953245.pdfIn PDF document text
    • http://vincityhomes.vn/wp-content/plugins/super-forms/uploads/php/files/apbq1f5out8l2e12j0qlllfkec/36953882707.pdfIn PDF document text
    • https://davidfauquemberg.com/home/fauquemb/david/bbdg_site/userfiles/file/95435341439.pdfIn PDF document text
    • http://vamaconsulting.sk/userfiles/file/42088713187.pdfIn PDF document text
    • https://gilbertems.com/videos/file/61996523985.pdfIn PDF document text
    • http://vksraja.in/fckeditor/upload/file/wuves.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/160eca4751da81---13409275943.pdfIn PDF document text
    • http://doktor-okonski.pl/uploadimg/file/70952175535.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a026cb433c1---sotapizopejuwubexaxevib.pdfIn PDF document text
    • https://astefin.ro/ckfinder/userfiles/files/93012797445.pdfIn PDF document text
    • http://nelly-design.ru/upload/files/62712687330.pdfIn PDF document text
    • https://betalinktech.com/blmedia/file/57427508279.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/ef5699a95d583a472d1402252cc4ee14/28029410450.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160acc9506604d---koveluj.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/65155065815.pdfIn PDF document text
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/579cf38725907774ba4d3229f3fe9a73/fapijawuj.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/684d418d23dfc0a2b77dde988efc4bfb/23003942516.pdfIn PDF document text
    • https://rjpexport.com/files/17687158516.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=what+is+is+lm+model+in+macroeconomicsPDF 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_off0001eefb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1EEFB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00020712.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x20712 10628 bytes
SHA-256: 2586ddcb7c1268c84c21723a390e6ea7f907537768996d2c2427f207de9ee642
font_02_sfnt_off00021f2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x21F2F 19980 bytes
SHA-256: e205f634ecab4c603dedbead7547cd2c54e143e636391f8f2d3c33e3668d6d5c