Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca88bc01a4da8395…

MALICIOUS

PDF

87.9 KB Created: 2021-10-04 11:55:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4944fbcecda3be5462f5e8aa196dc3e5 SHA-1: 3ea0062bf95b764f5a767e10a6811ead95ed1d63 SHA-256: ca88bc01a4da8395ae577552fd459300be8cefd773f1e05cebc5790f4e20d668
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 indicate the PDF contains a link farm pointing to compromised CMS uploads and disposable hosting, suggesting it's designed to redirect users to malicious sites. The presence of multiple external URIs and a link farm structure strongly suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9922

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://crewmak.ru/uplcv?utm_term=marriage+vows+in+tamil
    • http://www.juniorcollege.cl/ckfinder/userfiles/files/bifafadasikevoga.pdf
    • http://zs-oilfieldequip.ru/d/files/gowov.pdf
    • https://kingdom.vn/userfiles/file/kiwisozejiso.pdf
    • http://wpchkg.com/upload/image/file/xofimosimimisu.pdf
    • http://akkoryazilim.com/userfiles/file/59945010443.pdf
    • http://pileshoppen.dk/userfiles/file/jogulivamotilatexam.pdf
    • http://marketingnews.fr/images/file/mutadix.pdf
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614150076a824---77775019833.pdf
    • http://gzky.cn/dubeite/ckfinder/userfiles/files/20210903_193210.pdf
    • http://baove24h.org/upload/files/felilaxuv.pdf
    • https://smshealthcareservices.com/ckfinder/userfiles/files/92173501687.pdf
    • http://austral-immo.com/userfiles/files/51055119549.pdf
    • http://studiopedrazzini.eu/userfiles/files/livovex.pdf
    • http://www.rodnolespropertymanagement.com/siteuploads/editorimg/file/lilelojuxex.pdf
    • https://egokituz.eus/files/galeria/files/46437252021.pdf
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/l2p7gqutcrb9aui8khl4tgv4l5/negixodavu.pdf
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16139bf136aa37---76448608568.pdf
    • http://madiagranitosilano.it/userfiles/files/sinoxik.pdf
    • http://hiredriver.com/uploads/assets/files/99353417889.pdf
    • http://maxbrio.kr/files/files/jafuvifopasosutazu.pdf
    • http://xn--80aer5aza.xn--19-kmcm3c.xn--p1ai/ckfinder/userfiles/files/mudikig.pdf
    • https://qud27rxl1-k61l.com/contents/files/figopobik.pdf
    • http://www.mariabeckmann.com/fotos/uploads/files/fobeliwe.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16153cad73dfb0---26319689380.pdf
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/161412f0200fa7---sokinobatilo.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000da0f.bin
10020608cf4da21bc5bd90b70125b4202cb1122d7dfa39b0ccd9faeb8745e80f
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA0F 19400 bytes
font_01_sfnt_off00010b97.bin
8393e779c5094d531a6ec32aff9f85a0b52a247d0fb9977ad9b505ef3f7a1d9c
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B97 10596 bytes
font_02_sfnt_off000123d6.bin
6cba6677bde0f241d5abe4bd1daabf497e221bd6197b657de4268e87bbbbfee9
pdf-font-stream PDF embedded font (sfnt) at offset 0x123D6 16168 bytes
font_03_sfnt_off00013978.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13978 16792 bytes