Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1b86713bc3d7b47…

MALICIOUS

PDF

86.5 KB Created: 2021-09-02 15:28:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: da3e8093dfe826cc287da713dcb5e133 SHA-1: 3c2cc5a6bded0432ac4c262148ec1b903f065867 SHA-256: a1b86713bc3d7b47c45a9054d4a47c997dc400c013f9776f9c46edcaff458813
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document flagged by ML classifiers and ClamAV as malicious. It contains numerous URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics indicates a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://catamma.ru/uplcv?utm_term=teniasis+diagnostico+pdf
    • https://janeunchained.com/wp-content/plugins/super-forms/uploads/php/files/da9tfm6h7rdrll5k285s2qa7ba/29483930427.pdf
    • http://palenice.net/obrazky_clanky/file/jejupavamosesuvat.pdf
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/914uuktnqm854u0piekkngi6qo/81834743846.pdf
    • https://horgaszvelem.hu/ckfinder/userfiles/files/11058152161.pdf
    • http://itkaufmann.com/images/fckimages/file/niwepukatovivavu.pdf
    • http://barcelonahotel.vn/UpLoadFile/file/jopolawezarixul.pdf
    • https://youstore21.com/wp-content/plugins/super-forms/uploads/php/files/a3014f9262f5850e70f005fbda6328fd/wegiminekegurupefigafojev.pdf
    • http://mineraux-et-lithotherapie.fr/ckeditor/upload/files/44220166761.pdf
    • https://www.syah.org/wp-content/plugins/super-forms/uploads/php/files/dc500dc03f4567e11770f934f8d6cbb3/17636797293.pdf
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fc8aaa525b---tajavusowib.pdf
    • https://businesslife.com/content/file/43093592404.pdf
    • https://gamaconsultores.cl/upload/file/fosimud.pdf
    • https://qamarapps.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c0b0cac6704---77503134582.pdf
    • https://livresdarts.com/ckfinder/userfiles/files/3158320892.pdf
    • http://cokhihoaiduc.com/uploads/files/45428996944.pdf
    • https://hsse.cl/files/27883553927.pdf
    • https://unicon-msk.ru/data/files/5299071818.pdf
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6552b52de6---14132091460.pdf
    • http://benhvienlaptop.biz/userfiles/file/kokuwedi.pdf
    • https://infrastone.com/userfiles/files/91345046710.pdf
    • https://www.bocamvigliesrooms.com/wp-content/plugins/super-forms/uploads/php/files/215c3e32aea5d92aae457339e1120de7/pudevevinozibolaw.pdf
    • https://samiznojmo.cz/wp-content/plugins/super-forms/uploads/php/files/108f481816ef44fca9a35dfa2259dab8/4671162622.pdf
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161140759f3fb6---walugikababubonuv.pdf
    • http://kstarsmall.net/userfiles/file///43712071832.pdf
    • https://avela.md/userfiles/file/81592077162.pdf
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ff566be733---mopud.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_off0000ea67.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA67 16792 bytes
font_01_sfnt_off00010279.bin
16850213d11b9d7d43c4a7d9230fff3cc9c748a6a0b52b6ba45d3e16829e5eb0
pdf-font-stream PDF embedded font (sfnt) at offset 0x10279 19052 bytes
font_02_sfnt_off00013402.bin
5f48a1ce4edc1d5f1cd5eafe68dd9893d13fe4f82057ac925f8fccc9ae5c158e
pdf-font-stream PDF embedded font (sfnt) at offset 0x13402 10612 bytes