Malicious PDF — malware analysis report

Static analysis result for SHA-256 561faf40a1c48a2b…

MALICIOUS

PDF

99.9 KB Created: 2021-09-06 18:57:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c71dc2cc6a95cabbca10e6dd74e1578b SHA-1: cf4a5838feb5e396130a487cc36cbe4c9901b404 SHA-256: 561faf40a1c48a2b2999ee281144a5d54aa05850f2aaa7923adf63ef356ab2e9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to numerous other PDF files hosted on compromised WordPress sites and disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. While no scripts were directly extracted, the structure and URL patterns are consistent with a multi-stage attack where the initial PDF serves as a lure or downloader.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://arch-teh.com/pic/userfile/retawuzu.pdf
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/5ed9a72d693a4f899a20c4e5cb4f0dd4/12253459656.pdf
    • https://sunnyvale.com/wysiwygfiles/file/48855528777.pdf
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/160c2dd8c84b96---deduwomubixij.pdf
    • http://www.mearesandassociatesllc.com/siteuploads/editorimg/file/kigomuvabusiwizedozoxeto.pdf
    • http://tylincms.com/userfiles/files/171801283.pdf
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/172682be0d34f3fbfb73f4a4bbb2e238/92226003393.pdf
    • http://acpiindia.com/userfiles/file/wemumavisidojixu.pdf
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/b46d1ded3c7038206669b712d573636d/26438606577.pdf
    • http://massvt.sk/editor_uploads/system/files/lokebimetabevikafe.pdf
    • http://racecross.com/upload/edito_fckeditor/file/5754849391.pdf
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/16098c619a755f---35379773473.pdf
    • http://drinkandshrink.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608992b8ea161---xokidiwejevilu.pdf
    • https://kar360.com/resimler/files/89464646776.pdf
    • https://krossi.ru/images/content/files/pokasakudulepelewu.pdf
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c493600028---62123680511.pdf
    • https://pasarantogel2.com/contents//files/27106836454.pdf
    • http://yuhao-tech.com/userfiles/file/75997658495.pdf
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c45bdbe37dd---87834553472.pdf
    • http://vincitydata.com/uploads/ckfinder/files/tuvukepuleku.pdf
    • http://metapolar.hu/tmp/22196357357.pdf
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/9459e8bacdf386c6d2b40190f19b13e3/gebuninarobiripodug.pdf
    • https://www.bakirkoytemsilcisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160799ead0d129---32341235511.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=isekai+wa+smartphone+light+novel+english+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_off00011d5c.bin
3cab5ed6761adccedc55d5c95b3a6f9af373e528d70a5a1dda9e2abbb428e2b2
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D5C 11140 bytes
font_01_sfnt_off00013712.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13712 16792 bytes
font_02_sfnt_off00014f24.bin
cc1db07e0e18a955680a3e0689788913a440545cdfca9d9819b094f23c6f4a29
pdf-font-stream PDF embedded font (sfnt) at offset 0x14F24 19288 bytes