Malicious PDF — malware analysis report

Static analysis result for SHA-256 843136acc6e773da…

MALICIOUS

PDF

75.5 KB Created: 2021-09-02 19:30:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: bafb4ccf090d4661f856e472c2129554 SHA-1: b05628c86dcae80c67e76ab6e556fbc3234262f2 SHA-256: 843136acc6e773dad6c717230a878252902c4e0b722b0b124b09c9f95c352e0e
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as 'Pdf.Phishing.Trojan' and a machine learning classifier indicated a high probability of maliciousness. It contains numerous embedded URLs, many of which point to compromised CMS upload directories, suggesting a link farm designed to redirect users to malicious content. No scripts were extracted, and the document body was unreadable, but the heuristic firings strongly indicate a phishing or redirection attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607b4018d9d5a---wilam.pdf In PDF document text
    • https://wlao.on.ca/wp-content/plugins/super-forms/uploads/php/files/77fb4d0b7105ea1a70e88ffc0455a617/16323719229.pdfIn PDF document text
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/56e33d3a9888ef85cb901de9e1f2caf1/41514553796.pdfIn PDF document text
    • http://www.mbk-montage.nl/ckfinder/userfiles/files/47163420439.pdfIn PDF document text
    • http://jshanwoo.com/ckfinder/userfiles/files/383232763.pdfIn PDF document text
    • http://maurovalleferroarchitetto.eu/userfiles/files/sozigumolidosafegatufexim.pdfIn PDF document text
    • http://newbiesites.com/userfiles/file/pidugakorebiwarukobi.pdfIn PDF document text
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/utkumqlvokitt867hoegvp8tr2/97944150418.pdfIn PDF document text
    • http://motivationandmomentum.net/ci/userfiles/files/baxefagonajex.pdfIn PDF document text
    • http://lahma.pl/_u/userfiles/file/89613449932.pdfIn PDF document text
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094a6b7a0921---wokurulajexi.pdfIn PDF document text
    • http://geombiagioschettino.eu/userfiles/files/lakiluduwiloxedit.pdfIn PDF document text
    • http://dinskayarealty.ru/media/file/molupuzamup.pdfIn PDF document text
    • http://ct-tci.com/cttax/userfiles/files/90937364787.pdfIn PDF document text
    • http://eventcompany.org/clients/e/e3/e30ef11cf4efe639fe6592aa37b9cb94/File/35208308021.pdfIn PDF document text
    • http://saaretravel.ee/images/file/romebamajokipebuwumupawo.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d8a655b3b3---18573028230.pdfIn PDF document text
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cb20514910f---63368295720.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fe232fc8c11---41073431289.pdfIn PDF document text
    • http://risorsaterra.it/userfiles/files/83467070645.pdfIn PDF document text
    • http://www.gdchgs.com/admin/img/files/54367215285.pdfIn PDF document text
    • http://allseasonsart.com/uploads/fck_uploads/file/litezajepegipamozetexo.pdfIn PDF document text
    • http://thanhcongtechtra.com/upload/files/xojibizoxo.pdfIn PDF document text
    • http://minhledtran.com/luutru/files/mefupumemizijamafiten.pdfIn PDF document text
    • http://cuacuonnhanh.vn/Images_upload/files/mopomesetubafox.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=leadership+and+church+growth+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_off0000c219.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC219 10996 bytes
SHA-256: 2289111e23c45034aa9b04720536d992ceced4fbc39cdd4fd481d8578bf44223
font_01_sfnt_off0000db74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB74 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f386.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF386 17428 bytes
SHA-256: 286606d4c72406d69c72f1aa46f70ea660d63e23cd2de5c92fd357162a2da5ac