Malicious PDF — malware analysis report

Static analysis result for SHA-256 21b9ad91714172e2…

MALICIOUS

PDF

62.3 KB Created: 2021-08-16 06:50:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 0ae80b37214cea0b79a568a035a49421 SHA-1: 1d4f92599387e61a60addd30b279c0ed720a51c3 SHA-256: 21b9ad91714172e21bcd5a6bf225d71c07020db59a261b0d099622519d21e36e
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including ClamAV and an ML classifier, indicating malicious intent. It contains a link farm with numerous external URIs, many pointing to compromised CMS upload storage or disposable hosting, suggesting an attempt to obscure the final destination. While no scripts were explicitly extracted, the presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics, along with the ML_NYX_PDF_MALICIOUS flag, strongly suggests the document is designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9178

Heuristics 5

  • 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
  • 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 http://franzoesischebulldoggen.eu/userfiles/file/57155140024.pdf In PDF document text
    • http://escritacontabilidade.net/fotos/news/file/75787566436.pdfIn PDF document text
    • http://woodwork.pl/ubezpiecz/obrazy/file/33301433316.pdfIn PDF document text
    • https://247hvac.ca/fabulous1/uploads/files/27212999406.pdfIn PDF document text
    • https://dobski.pl/userfiles/file/ruwonuxajuw.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071bb243834d---83164256097.pdfIn PDF document text
    • http://otelm4b.ru/admin/ckfinder/userfiles/files/xetedorerizojotugesom.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/60a2677cc59da05e2a2200be7bae92fc/tinagivobobolalano.pdfIn PDF document text
    • http://jarosi.hu/files/file/36748974310.pdfIn PDF document text
    • https://menokatea.com/ckfinder/userfiles/files/wolamafaparukiwodevu.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c94a4b58c68---49541790819.pdfIn PDF document text
    • http://xn----otbb6ahq3d.xn--p1ai/ckfinder/userfiles/files/gefowuvaluvak.pdfIn PDF document text
    • https://xn--pssa17sw71b.tw/upimages/files/19052861328.pdfIn PDF document text
    • https://esterkins.de/ckfinder/userfiles/files/kujotajamazijukadaf.pdfIn PDF document text
    • https://sieuthigo.vn/upload/ck/files/78811065171.pdfIn PDF document text
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/3f58c77bde1cba2fc8542cff6b44ded2/82533394818.pdfIn PDF document text
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/f5ae825912bd833dec174de7bc554333/41806620021.pdfIn PDF document text
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607656cd5bd81---6613107897.pdfIn PDF document text
    • http://e-photo.lv/ckfinder/userfiles/files/25309938322.pdfIn PDF document text
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090c6afb6246---87457965508.pdfIn PDF document text
    • http://studiocommercialedelpiano.it/userfiles/files/69541915590.pdfIn PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606eb1cda7e26---28586106426.pdfIn PDF document text
    • http://altaprecision.com/userfiles/file/2727816232.pdfIn PDF document text
    • https://anyimaker.com/upload/users/files/tikikureserijaxi.pdfIn PDF document text
    • https://www.solucionaesp.com/ckfinder/userfiles/files/patezotokovowo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=jsc+result+2016+bd+marksheet+teletalkPDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e46a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE46A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1