Malicious PDF — malware analysis report

Static analysis result for SHA-256 c2c6851190ef8971…

MALICIOUS

PDF

85.4 KB Created: 2021-06-29 10:16:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 9908fd457e446432d18d8c0e1d40810a SHA-1: f56a77987fb3439b74bb953a16bd62dff402c6d8 SHA-256: c2c6851190ef8971539bc0b9d715fa40246f319432acc04e47302887b4d23708
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content to analyze, but the overall structure and URL analysis strongly suggest a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://aprilboya.com/userfiles/file/86109644555.pdf In PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607f78d727f95---kuburoparex.pdfIn PDF document text
    • http://atek-ent.com/upload/file/80696925376.pdfIn PDF document text
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089d43487e50---zisasa.pdfIn PDF document text
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/cdb5e75469a5aa8afae687cc4e853be5/gumepebikida.pdfIn PDF document text
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/ba88a8794945cffce2849559efc8ac09/45215342786.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16082bd74c292b---pejenejevetafozonar.pdfIn PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/8251527a66054b7a2431a5c84ab73942/zituzanazujenod.pdfIn PDF document text
    • http://tnslib.su/userfiles/files/87622900148.pdfIn PDF document text
    • https://eastmanllc.net/ckfinder/userfiles/files/41158048199.pdfIn PDF document text
    • http://tourister.kr/userfiles/file/24031001539.pdfIn PDF document text
    • http://www.bash.cl/media/file/91339063494.pdfIn PDF document text
    • https://manuscripthandler.com/userfiles/file/85956794670.pdfIn PDF document text
    • https://anmimar.com/royal/userfiles/file/24558875137.pdfIn PDF document text
    • https://www.profiemg.cz/upload/ck/files/4296670386.pdfIn PDF document text
    • http://f-kcc.jp/user_data/userfiles/files/90317245966.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad6b8570e8b---visiwofareb.pdfIn PDF document text
    • http://pamat.ro/UserFiles/file/32809601570.pdfIn PDF document text
    • http://whs1963.com/clients/7/75/758a827d59fb1c2827eec60421ffdc22/File/65590316939.pdfIn PDF document text
    • https://vibanghanoi.com/uploads/files/30076553485.pdfIn PDF document text
    • https://aquatrustfina.com/userfiles/file/37130757296.pdfIn PDF document text
    • http://www.homefacelifters.com/wp-content/plugins/super-forms/uploads/php/files/f7feed242428a958db9e0bf2eb5999e6/kekobexomikinifemeritej.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/28b6c4ed3d5fe728b4c88cbf7401a44b/dejamakenoturu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=red+clay+tennis+courtPDF 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_off0000e727.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE727 10624 bytes
SHA-256: c00b113227ddb61945993033ab53a8680194627d9309becec8535c2087d9716d
font_01_sfnt_off0000ff9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF9F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000117b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117B1 18712 bytes
SHA-256: 4250cd1d8da1f2276ebfd5cbc3779842e3f2953149f9e7edf7bc93f28e6055ae