Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8b96a706c653b61…

MALICIOUS

PDF

73.2 KB Created: 2021-09-03 19:56:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 6a8b580595c027059ecd79e5b4f4baea SHA-1: b5795a8c2d3c60538a74937c3f3afa351d671c0d SHA-256: b8b96a706c653b6115ceeaad656b0cb1b8ebe511156791f162827c7e6c6ec7fe
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be compromised or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a deliberate attempt to create a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://inwebjor.ru/uplcv?utm_term=hipertiroidismo+secundario+pdf PDF link annotation
    • http://suankaew.net/upload/userfile/files/65693787017.pdfIn PDF document text
    • https://mimpishio2bet.com/contents//files/tapigotalatokizaberamomub.pdfIn PDF document text
    • http://caphegiabao.com/upload/fck/file/kifep.pdfIn PDF document text
    • http://aircond.md/upload_fck/file/dubajunatanomulejodipu.pdfIn PDF document text
    • http://collegedelunion.com/clients/76066/File/15016631450.pdfIn PDF document text
    • http://nktrading.qa/file/files/23297421636.pdfIn PDF document text
    • http://maraulsan.com/ckfinder/userfiles/files/59270373995.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/kdanllo98ai44k037qmi37slu5/tajigurixajumarunujel.pdfIn PDF document text
    • https://perfecthospital.net/ckfinder/userfiles/files/72708791239.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/946c61f4c3ecfb6c1dd95978d5c49a22/69301560117.pdfIn PDF document text
    • https://makanbanyak.net/contents//files/kanudakufovumo.pdfIn PDF document text
    • https://casadko.fr/userfiles/file/4925071978.pdfIn PDF document text
    • http://versobrokers.eu/userfiles/files/71587533067.pdfIn PDF document text
    • https://dcmheavyequipment.com/admin/images/file/5780055170.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d3f6857ed39---sateli.pdfIn PDF document text
    • http://rallyteamwalraven.nl/file/fufesubodorodirofudat.pdfIn PDF document text
    • http://qkmedica.com/uploads/userfiles/file/25047142319.pdfIn PDF document text
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/f4f6bd219795939248c48fe5951f7463/11454825118.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/16073379e259a5---71806909348.pdfIn PDF document text
    • https://styliststudios.com/imagesTE/file/9869969120.pdfIn PDF document text
    • http://mp-journal.com/media/file/fafom.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae3cc5b173c---54492551519.pdfIn PDF document text
    • 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_off0000bc2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC2C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d443.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD443 10824 bytes
SHA-256: e0d717d9e26739d33cef95a1054bc9506e635776814578d8eb4582055d63834b
font_02_sfnt_off0000ed2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED2F 16728 bytes
SHA-256: 04796b704c34f57bc2fdd4355344dcae189f4806b6a8bfbf4b03ce81da0d121a