Malicious PDF — malware analysis report

Static analysis result for SHA-256 58ca41c847d87a02…

MALICIOUS

PDF

77.5 KB Created: 2021-06-23 02:59:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: e6a6ea3a6b7c9bd20d42e55e5c8dbea9 SHA-1: afeb7674f06c08e4e5cbc31323890ce4f98eda50 SHA-256: 58ca41c847d87a0215b262f44ec6124ba3cc8cf989b37a1a9f70de02e9d011f9
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous URLs, many of which are hosted on compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded content, though heavily obfuscated, appears to be related to the 'biggest loser calculator' and the wkhtmltopdf tool, suggesting a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a131ef05299---85051429562.pdf In PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087992dc8e6e---14176970512.pdfIn PDF document text
    • https://movesforfree.com/wp-content/plugins/super-forms/uploads/php/files/n794224crdfq2qj70nd9m9mbi4/33713029463.pdfIn PDF document text
    • https://andymullinscommercial.com/home/andy/public_html/ckfinder/userfiles/files/tipaveguwawiliwajem.pdfIn PDF document text
    • http://brmhn.com/userfiles/file/20210623024410_xp8hug.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160b3afea0cd10---10645348975.pdfIn PDF document text
    • https://www.westcountrystoves.co.uk/wp-content/plugins/super-forms/uploads/php/files/4965c21391d31969de34c0385c446360/dofepeparujamipurivuso.pdfIn PDF document text
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/be1d6d1a8ee09c234c4a8359c4a1562c/ragonoleviguwekaxefe.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/dg2nbu3iqennl6s97tnopkeivv/kujiwudozijovororod.pdfIn PDF document text
    • http://dienmattroigiasi.com/uploads/files/vobupodas.pdfIn PDF document text
    • http://bogelaipigeon.com/upload/file/mexafapidubinijusanifujax.pdfIn PDF document text
    • http://tantusmarina.com/UserFiles/file/54508803945.pdfIn PDF document text
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/3beeb6fa41eaf81cd01820b9005a41a4/97582972449.pdfIn PDF document text
    • https://elitestrategyglobal.com/wp-content/plugins/super-forms/uploads/php/files/bccbe1f98de94a428b08a7223a8fecd6/88760113979.pdfIn PDF document text
    • http://dichvuketoansg.com/luutru/files/75510145433.pdfIn PDF document text
    • http://zjpjxt.cn/upload/uploadfile/file/98957020604.pdfIn PDF document text
    • https://www.acetechnology.co.in/wp-content/plugins/super-forms/uploads/php/files/gvq1i27j5ua3i2k76g4n20dujt/xejusanawiji.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=the+biggest+loser+calculatorPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000efe6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFE6 5152 bytes
SHA-256: bd8f230d96aa61f7f050416bb49b7160d77703968774951774b4bf65a18c9628
font_01_sfnt_off0001016c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1016C 11516 bytes
SHA-256: 160d440705b364481ca80b92606b8062bb173f5213d055cb931263df0be27e48