Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb3b923bdbe35e94…

MALICIOUS

PDF

79.0 KB Created: 2021-09-01 15:23:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 080aea026f79f0ca2d0b3d46deb0ab94 SHA-1: ff4180191ade105c4ee945ebf2a0b950975bf77e SHA-256: cb3b923bdbe35e94e9ce10a553ec69d7efbb99f90a81008770383c2285a1c2d1
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as a link farm, with many URLs pointing to potentially compromised websites or disposable hosting. The ML classifier and ClamAV also identified it as malicious, specifically a phishing trojan. The document's structure and embedded links suggest an attempt to redirect users to external sites, likely for malicious purposes such as credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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://teewer.mn/ckfinder/userfiles/files/gimuxisubi.pdf
    • https://popcouncilinstitute.org/wp-content/plugins/super-forms/uploads/php/files/2de7767f3b39a6f441bbd144f53cbb80/49161960743.pdf
    • https://shayangroup.net/wp-content/plugins/super-forms/uploads/php/files/a8e3de15bb244bc4b9b9573e7ae9692a/77462419927.pdf
    • https://bettyloupaints.com/userfiles/files/majovokatefaze.pdf
    • http://animationcoach.com/userfiles/file/35390463758.pdf
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/ck6qv9tikb7giv1g0eqr0ndhj3/sufaf.pdf
    • https://cytairtool.com/test/userfiles/file/20210617_e0aff.pdf
    • http://bitite.lv/media/txt/122/file/potir.pdf
    • http://avalon-essenzen.at/userfiles/file/piluded.pdf
    • https://www.ojchamber.com/ckfinder/userfiles/files/31379067629.pdf
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/fa4276d14f189ce3db9ae8253713e2cb/tagikavakolin.pdf
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/160d3b0f58cefa---48837868963.pdf
    • http://locke-3c.tw/uploads//files/202108031003117990.pdf
    • https://zapret-rf.org/web/img/podborky/files/vuwizepem.pdf
    • http://yearbookplus.com/uploads/ckfinder/files/80963628374.pdf
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/a3447f77fb54eb4eff8aebfdabe53413/23480712862.pdf
    • http://jagatjyotischool.org/jagatjyotischool/userfiles/file/jewofunujekiteregepox.pdf
    • http://cablexconsulting.com/Upload/file/77469931.pdf
    • http://21cedu.com/pds/userfiles/files/3221710679.pdf
    • http://sobinco.cz/ckfinder/userfiles/files/dekimemefiturokezibeg.pdf
    • https://twr1115.net/files/fckeditor/file/vuzowobomiza.pdf
    • https://travelinnsuites.com/nbloom/fckuploads/file/gugana.pdf
    • http://www.lebedosapartotel.com/data/yukle/files/poragusajuwixulasibofumiv.pdf
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/368c760c07db10a79916ff513f32b58f/78705779178.pdf
    • https://eldorado777.ro/upload/editor/file/nazexewaluromesov.pdf
    • http://skene.es/userfiles/file/ralebediwegozofodusu.pdf
    • https://morabia.fi/images/file/83041688015.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=hayden+panettiere+law+and+order+svu
    • 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_off0000d1b3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD1B3 16792 bytes
font_01_sfnt_off0000e9ca.bin
3c3b007316a1e59b8815a67feb3673e5d65ec34063e24d393e618e9ff9cccc22
pdf-font-stream PDF embedded font (sfnt) at offset 0xE9CA 10744 bytes
font_02_sfnt_off00010299.bin
273ed8130ee60ec993a9a7d3a5c52f21a6a4e5d1370c1354881570ac4149948e
pdf-font-stream PDF embedded font (sfnt) at offset 0x10299 16776 bytes