Malicious PDF — malware analysis report

Static analysis result for SHA-256 6cb1cf61614c9fde…

MALICIOUS

PDF

84.5 KB Created: 2021-09-12 22:21:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 9c4fcedc4abd9bc777f8aa5ac7de10cb SHA-1: 69d1c609885af07bcbcdf6302c2477a184e4bb96 SHA-256: 6cb1cf61614c9fde3d811c2e1829671e353d741438585b5770f3068b5048fdb4
156 Risk Score

Malware Insights

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

The file is a PDF that contains numerous embedded URLs, many of which point to other PDF files hosted on various domains. This behavior is indicative of a link farm, potentially used for SEO manipulation or to distribute further malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or trojan distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://riwg.in/userfiles/file/gigixotu.pdf In PDF document text
    • http://fitviewer.info/files/file/73845050477.pdfIn PDF document text
    • http://nadafashionbelt.com/Uploads/file/34041277406.pdfIn PDF document text
    • https://danfort.lv/userfiles/file/gumomufisuz.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16136fd174659e---gaviberapofofefi.pdfIn PDF document text
    • http://gucaoyun.com/uploads/file/012147162767.pdfIn PDF document text
    • http://mashhadgardi724.ir/basefile/mashhadgardi724/files/gazeregirokuba.pdfIn PDF document text
    • http://charontrade.hu/data/file/10902686195.pdfIn PDF document text
    • https://loffoxfitness.mvwebsolution.com/userfiles/files/50067933591.pdfIn PDF document text
    • http://favorit.pl/userfiles/file/pilamifogebuzejavur.pdfIn PDF document text
    • http://imhkayseri.com/resimler/files/51200246543.pdfIn PDF document text
    • http://mylodge-naoshima.com/images/blog/file/4639001301.pdfIn PDF document text
    • http://erago.cidees.com/uploads/files/xurazevo.pdfIn PDF document text
    • http://bharatdarshan.net/rgroup/ckfinder/userfiles/files/5618626884.pdfIn PDF document text
    • http://eros-arena.name/eros/userfiles/file/35016796412.pdfIn PDF document text
    • http://guchen.ru/d/files/95393335894.pdfIn PDF document text
    • https://nmcs.ca/userfiles/files/limunixumubojufikuzevolu.pdfIn PDF document text
    • http://321eastern-thailand.com/userfiles/files/37918594539.pdfIn PDF document text
    • http://tns-china.cn/editor_upload_image/file/talatuzazenejanonuxiso.pdfIn PDF document text
    • http://jj-metals.com/userfiles/file/2021090513442873499.pdfIn PDF document text
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613cd92183534---28948052073.pdfIn PDF document text
    • http://gpsputhuppally.com/userfiles/file/24136473830.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/161365c9432834---tibotifimufabawuzexik.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=tamil+new+full+movie+2021PDF 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_off0000e4ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4EC 18388 bytes
SHA-256: cd08b6ebfc0d1c9ca7a6385c68f051a476396f786d25d785ba614bf4d83c7e5a
font_01_sfnt_off00011456.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11456 10516 bytes
SHA-256: 62be2153b6ffa7dcdb7edbd27c719dc939e79472a54348b7a3be9b3721547147
font_02_sfnt_off00012c5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C5B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1