Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8b7edc2881a78f0…

MALICIOUS

PDF

73.4 KB Created: 2021-09-05 16:24:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0da544f4c4e134a422c83afbea92ee02 SHA-1: 4d25923f682899d6093f2593aa4314d222f45cdf SHA-256: b8b7edc2881a78f08f59e91620c9f354615fff902c1fa2dbfdfb293066e8a44a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to obscure the final destination. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. While no scripts were explicitly extracted, the nature of the URLs and the 'link farm' heuristics point towards an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://kontiko.com/ktkweb3/images/upload/files/41990063388.pdf
    • https://glowskincare.net/wp-content/plugins/super-forms/uploads/php/files/988d3ca382c02ca18479e10330d0337c/60109302269.pdf
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/4c140f589b8d29f75504fad2204042d9/15262191673.pdf
    • http://austintownfitch1980.com/clients/879833/File/91939882699.pdf
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/c7dd49ab2c9bfd165be6e5283f078acb/91370762028.pdf
    • http://mitchelllawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/sadibevuf.pdf
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/160701dbb281f1---37589232572.pdf
    • https://nicklason.se/ckfinder/userfiles/files/44204836662.pdf
    • https://a-1commercialkitchenservices.com/ckfinder/userfiles/files/xupusirovolopu.pdf
    • https://rajatotogroup1.com/contents//files/17335722110.pdf
    • http://ressourcengarten.de/azubi/userfiles/files/buzifolevirato.pdf
    • https://voolabs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b15e4f1e0cc---votawevufuwirizon.pdf
    • https://mimpishio1.com/contents//files/pakudegajamisove.pdf
    • http://www.brickchamber.com/ckfinder/userfiles/files/54803045698.pdf
    • https://remoteyourstaff.com/calisma2/files/uploads/23791404893.pdf
    • http://thaimassagemodel.com/ckfinder/userfiles/files/99330263857.pdf
    • http://mtcongnghiepxanh.com/upload/fckimagesfile/juwitadajud.pdf
    • https://ateliersmq.com/pevron/www/img/file/jorelufilopinojuxomovase.pdf
    • http://epwuae.com/userfiles/file/61255418555.pdf
    • http://sp3siemianowice.pl/userFiles/files/riwakagotafoka.pdf
    • https://samiznojmo.cz/wp-content/plugins/super-forms/uploads/php/files/5fdba74ad56e23d264fb966bf786643c/85430045286.pdf
    • https://andrejc.si/files/file/derajevasilaf.pdf
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/160cb2dbaee417---jifawazuzujoluxarugajiwet.pdf
    • http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160b3e57346998---91027437501.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=tdah+definicion+segun+autores+pdf
    • 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_off0000c0d8.bin
aaccfeb8785ea447e799d7bfd718fd2feb42483d04c0b0cc55fa8673e500e110
pdf-font-stream PDF embedded font (sfnt) at offset 0xC0D8 15308 bytes
font_01_sfnt_off0000e6a5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE6A5 16792 bytes
font_02_sfnt_off0000febc.bin
758b8cbe907a843de2348fa516199e9633a95b95935ad5555857a9e3a76ff4a7
pdf-font-stream PDF embedded font (sfnt) at offset 0xFEBC 10916 bytes