Malicious PDF — malware analysis report

Static analysis result for SHA-256 36d8312a2c26dac3…

MALICIOUS

PDF

73.7 KB Created: 2021-09-21 19:57:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 312ad707b43e13410b9d16e48452abe5 SHA-1: 18eae64e3c25724c85ac29a027e9ed60a94925d2 SHA-256: 36d8312a2c26dac328fbd446b91b01353b34e1adec639967ece6876fae4f2716
156 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ML classifiers and ClamAV. It contains numerous links pointing to compromised websites, suggesting a phishing or redirection attack. The heuristic firings indicate it's a link farm on disposable hosting, likely intended to lead users to malicious content or further exploits.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/161419daee534c---43993123900.pdf
    • http://alemotta.com/resources/original/file/50617208839.pdf
    • http://files.ibiza-ferien.de/file/40028313005.pdf
    • https://gulceoyunlar.com/calisma2/files/uploads/40479946965.pdf
    • http://stadion-zarya.ru/ckfinder/userfiles/files/7170903934.pdf
    • http://fillaracingacademy.cz/ckfinder/userfiles/files/zikidesafove.pdf
    • https://sportsslife.net/upload/ckfinder/files/92361032496.pdf
    • http://gpszone.hu/upload/userfiles/file/dosomemavosafubowim.pdf
    • https://eminentland.com/admin/userfiles/files/jazomewuxewejume.pdf
    • http://rrbrentacars.com/files/others/83128934119.pdf
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/1613d61c1478e0---56983222167.pdf
    • https://www.traitagri-solutions-alternatives.fr/ckfinder/userfiles/files/40461387176.pdf
    • http://okna-stv.ru/userfiles/files/wududivugevuxoxutesufom.pdf
    • http://cabini.it/userfiles/files/sexolutize.pdf
    • http://biswasi.com/userfiles/files/36067376986.pdf
    • http://mariancozma.com/_user/file/94317610806.pdf
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/16133a55c1b23e---ritar.pdf
    • http://skncn.com/u/files/xabewedurav.pdf
    • http://speckrepej.com/upload/file/tejikisigokolanamorar.pdf
    • https://www.hmgfinance.com/ckfinder/userfiles/files/mevoj.pdf
    • http://globalbizkorea.com/userData/board/file/kavudidubogetas.pdf
    • http://orenprom.com/img/account/file/mutenezik.pdf
    • http://bushurov.ru/images/files/sokurigizemaxesijo.pdf
    • http://hanabi-la.com/uploads/files/mojebuzubavi.pdf
    • https://hostsolutions.ro/app/webroot/files/userfiles/files/67413788608.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=octal+to+hexadecimal+conversion+examples
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bdf8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBDF8 16792 bytes
font_01_sfnt_off0000d60f.bin
1aba9dadeb19c101d0d35d78a0824d2c9d29ad8031f2b1a8b324d37c7b18bd9e
pdf-font-stream PDF embedded font (sfnt) at offset 0xD60F 10972 bytes
font_02_sfnt_off0000ef64.bin
20bd19b184d81633158ae8924b940ca2c8ff50311b611fed26b1dde390d7ee84
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF64 16204 bytes