Malicious PDF — malware analysis report

Static analysis result for SHA-256 5df4828c31316527…

MALICIOUS

PDF

86.4 KB Created: 2021-07-06 08:53:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e9d02d4c2dc88c2928850e5b7e72ab0c SHA-1: 5fe1ead9b0302ef5e4023771dcab08c465e1efd0 SHA-256: 5df4828c313165274e5abe117afe24eadf78bec5983876bb9db343b1b8d4d67d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to numerous compromised WordPress sites, which in turn host other malicious PDFs. This suggests a multi-stage attack, likely initiated via spearphishing, where the initial PDF serves as a lure to download further malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://www.apartamentselsllacs.com/wp-content/plugins/super-forms/uploads/php/files/7k7aduvstqj26ak6viaffqaafa/korotodojodimekunewav.pdf
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/16094ca8d4fef3---satujuxu.pdf
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/s73q05bh7eehur8o95ltenoc76/3617064929.pdf
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608b3c89cb4e8---nesusarepodedidojipafoxu.pdf
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/9fmkm7s6dg08qcjnrcfq8m292j/5703558373.pdf
    • http://adria-ex.com/images/blog//file/jebinolinano.pdf
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/377ff1f38ad8c7b101e6ae0a813d4092/87027426661.pdf
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074010dcb308---dutumuxisibegogufuk.pdf
    • http://la-roofers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160bd8e0179de9---84965333477.pdf
    • http://altelaw.com/uploads/image/file/xebori.pdf
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4de84ab45e---zofowi.pdf
    • https://www.groupenahno.com/wp-content/plugins/super-forms/uploads/php/files/kt50ei25kp3qgg4c7pjd3j3juh/vefefalevazabidos.pdf
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a12b206327a---40052351659.pdf
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c65237d207e---43550818188.pdf
    • http://22743333.com/userfiles/files/menukurovabiselekegej.pdf
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/160775a61288b0---40914981463.pdf
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cd16496b389---56358103855.pdf
    • http://media-production.net/admin/ckfinder/userfiles/files/jesebumakosajun.pdf
    • https://thuaphatlaihanoi.net/uploads/files/34866992211.pdf
    • http://www.knickmeier.net/images/pageimg/file/miwavusipinabuwogojij.pdf
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160880287aa0ba---95282960754.pdf
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a340b6ee408---mozoxinavamo.pdf
    • http://chataphan.com/file_media/file_image/file/61023477545.pdf
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/i704j771fe9j6a5auocd9i4034/93820755934.pdf
    • https://detectiveoffice.net/userfiles/file/tiwenidimizaje.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=m39+bayonet+for+sale
    • 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_off0000ebee.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEBEE 16792 bytes
font_01_sfnt_off00010400.bin
d1a62316f7ae5fe5b2f00805af59e48b7f6b85e71c1705b62c862f4c0dcdf57c
pdf-font-stream PDF embedded font (sfnt) at offset 0x10400 18276 bytes
font_02_sfnt_off000133a9.bin
b4bf089a3998a25de3dd6975ce7d1feaffaf7616cb6129e6811eeff5083a60ab
pdf-font-stream PDF embedded font (sfnt) at offset 0x133A9 10704 bytes