Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8582b78388daeb5…

MALICIOUS

PDF

137.4 KB Created: 2021-07-14 10:53:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 4b99f3bed59dca3a0b7858087441c193 SHA-1: f46347a61da3435e20236470c97e30e64c4671c7 SHA-256: b8582b78388daeb56f4ee7bd69d6f005cf45b71bb3547a873d90384065df25a8
124 Risk Score

Malware Insights

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

The PDF file contains a large number of links, many of which point to compromised WordPress upload directories, indicating a link farm designed to redirect users to potentially malicious content. The ClamAV detection as 'Pdf.Phishing.Trojan' further supports its malicious nature. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier suspicious score 0.3082

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://entone.es/wp-content/plugins/super-forms/uploads/php/files/08d4e6a0dfc811c0d1c9e70a1f816e37/rigor.pdf In PDF document text
    • https://koratspring.com/upload/file/39909611701.pdfIn PDF document text
    • http://ghalemdi.com/userfiles/file/jiseze.pdfIn PDF document text
    • https://kisikana.hr/UserFiles/files/27398279724.pdfIn PDF document text
    • https://www.amiunaorchestra.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160ac121bf00f1---sajavawoxipaxef.pdfIn PDF document text
    • http://gentlemensquartersbarbershop.com/wp-content/plugins/super-forms/uploads/php/files/b91ea315e2d633ab07fd652c5c68c709/vubufoniz.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160711f45a8b06---263064023.pdfIn PDF document text
    • https://www.opdrrustukalac.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd29e3aaba3---felogudefaxiv.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608cdf6391369---62793566802.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606f7ed53f03e---xibeguzutizuwozupalolu.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16074d50d60fc5---25004107030.pdfIn PDF document text
    • http://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093c05d278ca---9855162514.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/624da1ec5809d15bf0545f501c73399f/bewapexat.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/j28bc3cs40657b8lbd7hv8p5o4/98053823829.pdfIn PDF document text
    • https://www.lashharmony.co.uk/wp-content/plugins/super-forms/uploads/php/files/lnmnmk0qf008sal2mmotd08rgi/43277901103.pdfIn PDF document text
    • http://zpb-maciejewski.pl/upload/fck/file/gopanifut.pdfIn PDF document text
    • http://neuragen.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160cb8b5fa9295---15419801861.pdfIn PDF document text
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090e1b09849a---zijabaxuvonelubatevobaber.pdfIn PDF document text
    • http://agcslohian.com/userfiles/file/biwej.pdfIn PDF document text
    • http://bhs-class1957.com/clients/35434/File/81116717581.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160896810557fc---togopujete.pdfIn PDF document text
    • https://abugfreemind.com/userfiles/file/48257362411.pdfIn PDF document text
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/97eaeb6cbe4188f3161fed0f0811ffe2/9860607927.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=different+types+of+aphasiaPDF link annotation
    • 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_off0001c779.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C779 10524 bytes
SHA-256: 329fb1d59b513fec5c5631dd5b08c502f4258b676d49fc98812e232164c101d4
font_01_sfnt_off0001df6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1DF6E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001f780.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1F780 19988 bytes
SHA-256: 0b46beca7a923e3d6fb25ce1d479b4b457a6336ca0f82e5448341dd885931eb0