Malicious PDF — malware analysis report

Static analysis result for SHA-256 52c35b6712b3a1bc…

MALICIOUS

PDF

74.1 KB Created: 2021-09-05 22:51:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: b8beb0b3c05af7d05a7cb8c61ba86796 SHA-1: 82f323944b7916408bbed3ba1840aa6f0e400df1 SHA-256: 52c35b6712b3a1bc78eecc09cbe66552f1c65f30c9dbddbce5f9fcf3364e5be9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm with numerous URLs pointing to compromised WordPress sites and disposable hosting, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of multiple external URIs and link farm heuristics points towards an attempt to redirect users to malicious content.

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://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/sdo0101l23mngjprsgi7ftl9i3/rexekafuvurokakamobodozu.pdf In PDF document text
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/10bc49c3f59f53067f9da183e94b42db/80726731200.pdfIn PDF document text
    • https://agros.net/uploads/file/42776910126.pdfIn PDF document text
    • http://dryoucosmeceutical.com/userfiles/files/41789149373.pdfIn PDF document text
    • https://gulfcans.com/home/madarmun/public_html/gulfcans/images/bulk_images/files/35449603538.pdfIn PDF document text
    • http://xn----otbbfbbknchz.xn--p1ai/sadm_files/93001792213.pdfIn PDF document text
    • http://casaalu.com/luutru/files/levifefoxirawi.pdfIn PDF document text
    • http://bjhtdszdh.com/v15/Upload/file/202167121529521.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16090790fbad97---nonal.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f5b62c65a4f---94373199350.pdfIn PDF document text
    • https://freedomtampons.com/wp-content/plugins/super-forms/uploads/php/files/c310f03ca3859c2c1dde9dc933ec96d7/29565268113.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/160fc792301cd2---zefinopibibalugujizajeta.pdfIn PDF document text
    • https://jaurrieta.net/USERFILES_JAURRIETA/files/89852660793.pdfIn PDF document text
    • http://www.contectrade.hu/fckfiles/file/valol.pdfIn PDF document text
    • https://copyjokertw.aw6.tw/uploadfile/qu4_qu106_com/files/93858577694.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8c6feeccac---peden.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/uuga0p0rj95hg12mu2bo9uuhm9/20100961016.pdfIn PDF document text
    • https://pakianco.ir/data/image/uploads/news/files/tedelibusovimexamixituti.pdfIn PDF document text
    • http://wadirumshootingstars.com/userfiles/file///gixusajiw.pdfIn PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160728b5d5de7e---sujimasazesapeju.pdfIn PDF document text
    • http://hhsbluebirds1967.com/clients/b/b5/b592d679e9980e62d9d56be1bfb8b6b6/File/migufakadokoxuragita.pdfIn PDF document text
    • http://bitite.lv/media/txt/122/file/64016870606.pdfIn PDF document text
    • http://futureinfashion.com/ckfinder/userfiles/files/xipajimivugubedupi.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/io08fkcdgs8kt3h1i8r3elofuj/97961604746.pdfIn PDF document text
    • http://poltinik.ru/userfiles/file/wegusebukerewakazixezupa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=gym+program+for+muscle+gain+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_off0000c0b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0B4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d8c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8C6 15936 bytes
SHA-256: 25326c096a8cdd1e95cb9fd7d2590a09da8024d81913b7057286da56c7f1e336
font_02_sfnt_off000100de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100DE 11116 bytes
SHA-256: 988b49ca97ddce685742239860f6cd28725ff95b5fa5baaaa73484a56d81f2d7