Malicious PDF — malware analysis report

Static analysis result for SHA-256 772198c3e89e73b3…

MALICIOUS

PDF

97.2 KB Created: 2021-07-05 17:26:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 72b58a62191ceb7b16546a5d0e759459 SHA-1: 5e8ead087da775b8651360c489c93f4f45d0b01f SHA-256: 772198c3e89e73b37c267771ab2207517b0adb32eceb64b2d112301310e4e4e2
156 Risk Score

Malware Insights

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

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains numerous external links, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users. The primary attack pattern involves luring users to these external sites, which likely host phishing content or further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9929

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://crewmak.ru/uplcv?utm_term=combinatorial+game+theory+pdf PDF link annotation
    • http://renovator.cz/files/file/26273224576.pdfIn PDF document text
    • https://digireg.nz/upload/25024098628.pdfIn PDF document text
    • http://debsluxe.com/clients/1/17/174397649ed9f07baa8f9d9f48c72a4d/File/51546363314.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/4c334be1defc6cfe28d87fa6032ed9c2/4069711494.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ebc5fd9bd0---guxalekudugolomofenimewi.pdfIn PDF document text
    • http://fcv-bo.org/data/fcv-bo/userfiles/file/41878345355.pdfIn PDF document text
    • https://nhathuydesign.com/wp-content/plugins/super-forms/uploads/php/files/b29k6uro2b3i71hso8t74d6cad/dalepiximevisaxewa.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160abb66794337---lufadujazejobi.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b2314078354---10701330924.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/jjfg715hdme2grft68br2upeu8/37239413719.pdfIn PDF document text
    • http://kimbuunguyen.com/uploads/userfiles/file/87554997729.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160752344b96e1---14167938859.pdfIn PDF document text
    • https://chungcungoaigiao.net/uploads/files/23159179712.pdfIn PDF document text
    • https://morabia.fi/images/file/84319831868.pdfIn PDF document text
    • http://ghhs1968.com/clients/5/57/5762190d0a265df614d1f295a7060a42/File/2666420843.pdfIn PDF document text
    • https://www.bocamvigliesrooms.com/wp-content/plugins/super-forms/uploads/php/files/1f739637bd71b546698a6a5acc5955e2/witoduzulaxeredemuluzawiz.pdfIn PDF document text
    • http://bahattinburyan.com/userfiles/file/9464507231.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7ef30535b9---48027913052.pdfIn PDF document text
    • http://tavernadelsnoguers.com/wp-content/plugins/super-forms/uploads/php/files/eda903922bad95e3d51e1be3739ae088/95332416500.pdfIn PDF document text
    • https://www.stamfordtaxis.com/wp-content/plugins/super-forms/uploads/php/files/1hqephg3v0spdru1cjsujngois/31165740575.pdfIn PDF document text
    • https://securitydm.com/slicice/file/muweparudetagilebonokir.pdfIn PDF document text
    • http://accessprecision.com/userfiles/file/79985233479.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd53cb9614e---61098512970.pdfIn PDF document text
    • https://jagamimpi.org/contents//files/39264011107.pdfIn PDF document text
    • https://zanhotel.ro/beficientconsultingFiles/file/60263501010.pdfIn PDF document text
    • 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_off000117ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117EE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00013000.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13000 17948 bytes
SHA-256: b4af2276d3f72b1fcccec8ed6afe605766f7fc5facba96501eb5bb21d87ece43
font_02_sfnt_off00015e3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15E3D 11060 bytes
SHA-256: 1bf6e11b3bf9e08780264d37349155d38b7f296f51389b366f2a65a1b3650c1e