Malicious PDF — malware analysis report

Static analysis result for SHA-256 87b75ded058e6ab3…

MALICIOUS

PDF

75.6 KB Created: 2021-09-08 06:33:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 6f12f46b246ae9007be16d87f99aef7b SHA-1: abd193998253947da5094dbfa61ad67866d33f0c SHA-256: 87b75ded058e6ab31af10c532838f3bf3a48b4374bcd545bb3ee88599e8f40da
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, and heuristics indicate it functions as a link farm. Multiple URLs point to compromised WordPress sites, suggesting an attempt to distribute malicious content or phishing lures. The document body is unreadable, but the presence of numerous links and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly suggest a malicious intent to redirect users.

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 http://endustriyelkiralama.com/wp-content/plugins/super-forms/uploads/php/files/r3hrm37dkib5p5fl2eeb21lgre/bexelakipipo.pdf In PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610e72b9e4c72---75783866718.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160847d8bcd7d2---6451619789.pdfIn PDF document text
    • https://bomberosdenavarra.com/userfiles_nexo/files/gevozikemumegikizox.pdfIn PDF document text
    • http://kapli74.ru/upload_picture/forimikepatogetimuwu.pdfIn PDF document text
    • http://uniondrygoods.com/fckeditor/userfiles/file/tajapina.pdfIn PDF document text
    • http://www.ecostroyservis.ru/File/50759602086.pdfIn PDF document text
    • http://tiyuchangdi.com/upload_files/files/20210713_155120.pdfIn PDF document text
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/cd1c96fa0b104d0a9a0af915eaca6faf/dimelajixofop.pdfIn PDF document text
    • https://ce-mi.pl/uploads/userfiles/files/xafawibatorenisi.pdfIn PDF document text
    • http://zgkimsteszew.pl/img/upload/files/4215072092.pdfIn PDF document text
    • http://www.bash.cl/media/file/33890396767.pdfIn PDF document text
    • https://jgmurphy.com/wp-content/plugins/super-forms/uploads/php/files/e5b4a5bd4e7d3be6fc1166b009488ee6/mizibenidalilutupatu.pdfIn PDF document text
    • https://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/b460cdfcbc9ef38b52e4d08ff9a82abd/vataxokunewavaxu.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/160b5d78b60fd8---namazoxapazimenokokarudod.pdfIn PDF document text
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/850a9f73b18dc2cfd1c9891be1836734/solagijuzitasolizelozo.pdfIn PDF document text
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607845f59c82c---87643204288.pdfIn PDF document text
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/2888b8eb0c4a35a4a332740919da79f1/lenoxopixizijexobu.pdfIn PDF document text
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/0af2619ecc2322db494f2d2f01b1275d/zefaragogolebimapok.pdfIn PDF document text
    • http://envisystem.com/upload/userfile/files/luluwuzuxozefelilosedar.pdfIn PDF document text
    • http://tnslib.net/userfiles/files/79655221088.pdfIn PDF document text
    • http://skiflogistics.ru/userfiles/file/81142198403.pdfIn PDF document text
    • http://gphs100.com/clients/e/e3/e3ed30f4e85b1ff1e74f61348c82e8eb/File/pexewemifo.pdfIn PDF document text
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/05b93fc5e4207eb84e8b6fb0a38b845f/71517294017.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a49f383a18---tiwevalowoxixefuruke.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=petlog+transfer+of+keepership+pdfPDF 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_off0000c456.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC456 16652 bytes
SHA-256: 0c17dede889f9d6786e449b8838013f57db24cbb5ed62ab39d81c4910180f344
font_01_sfnt_off0000ef16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF16 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001072d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1072D 10872 bytes
SHA-256: 1a38e2a02a1aa3a53fab0f67af1ea06eaa0c8cac41fa634f4c1ea83f24d3960d