Malicious PDF — malware analysis report

Static analysis result for SHA-256 b656bcb274a34519…

MALICIOUS

PDF

88.4 KB Created: 2021-07-16 05:41:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: c99984b7095462df96bfa4d1a5611396 SHA-1: f5ac9af5129248679a77930cbbdea303bf437d59 SHA-256: b656bcb274a34519aee64c8c5aa2c3ab5ba2fbc0ebad0152e49f92a12080e5dd
96 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites utilizing the Formcraft plugin for file uploads. The ML classifier strongly indicated maliciousness. The primary function appears to be directing users to potentially malicious or SEO-abused content hosted on these compromised platforms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 5

  • 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 http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608805095a58c---53328905220.pdf In PDF document text
    • http://eventechsite.com/files/files/43289168036.pdfIn PDF document text
    • http://amouage-salon.ru/admin/ckfinder/userfiles/files/fakivasibogigokazulo.pdfIn PDF document text
    • https://www.axelendinggroup.com/wp-content/plugins/super-forms/uploads/php/files/150c80b293f0c8babed2c4f5b98a4277/74438584820.pdfIn PDF document text
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c6d622af01f---pagegezobon.pdfIn PDF document text
    • http://vasvaripalmuzeum.hu/upload/file/5840940839.pdfIn PDF document text
    • https://homini.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16074092942a66---bilegozukev.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160ac963ee852c---88774772432.pdfIn PDF document text
    • http://provia-events.de/pics/fotos/1/file/69678412106.pdfIn PDF document text
    • https://cedarcreeksauce.com/wp-content/plugins/super-forms/uploads/php/files/cbd1ad4ee0b2b6fdefb51828a766418e/13012174237.pdfIn PDF document text
    • https://catherinehourihan.art/wp-content/plugins/super-forms/uploads/php/files/3160eba298b005e7fc67dac7d05ab80d/26060485837.pdfIn PDF document text
    • http://jpmoto.biz/upload_picture/43041153053.pdfIn PDF document text
    • https://www.uniqueartzz.com/wp-content/plugins/super-forms/uploads/php/files/7pm04srbsb5me4qiuiqmcttf2k/nopejotuxasigemaxuza.pdfIn PDF document text
    • http://colleges-in-tamilnadu.com/FCKeditor/userfiles/file/tarusasunulapanitexev.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/f3b28cfb9ee1a75023e5bc18e5e6849f/xodifuwopuruluravude.pdfIn PDF document text
    • http://amon-syotengai.com/userfiles/file/taxopolajumo.pdfIn PDF document text
    • http://2ds-creations.fr/userfiles/file/kakekak.pdfIn PDF document text
    • http://gpszone.hu/upload/userfiles/file/76680613082.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160997186ac748---68879691301.pdfIn PDF document text
    • http://luxcottage.ru/stroykamen/userfiles/files/nofekikawosoveraxagexixu.pdfIn PDF document text
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085af17bd50b---larivonisabejikapojima.pdfIn PDF document text
    • https://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/f38632713892cae3a4dffa7367f0caf9/tidajoterebafaxake.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607a32a16b66d---vafavemimuzapazowe.pdfIn PDF document text
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/a3brgtn0j0h8dqa7lajdk5b2j7/tovedob.pdfIn PDF document text
    • http://luxmeterthai.com/ckfinder/userfiles/files/rijoxodusujagomorex.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=plant+having+autotrophic+and+heterotrophic+mode+of+nutritionPDF 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_off0000f53d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF53D 11068 bytes
SHA-256: dfe3d270c9947420c7197043375a17605c6307e50e0f04fb31a773d569581834
font_01_sfnt_off00010e9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E9D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000126af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126AF 17160 bytes
SHA-256: bdaa9558e892e1641ccff59d9a26e0199b3931c8384d97bcc693239e57ff0404