Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbec31594d56091d…

MALICIOUS

PDF

80.5 KB Created: 2021-09-23 00:03:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 37715640b79ae4dd695ca52e65ff6353 SHA-1: 6abfef3d834b339883ad9dfc7e55248c7ab8c1ba SHA-256: cbec31594d56091d8d3d6a965a9692020bd956acd25924559c79561402fe032f
156 Risk Score

Malware Insights

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

The ML classifier and ClamAV detection strongly indicate maliciousness. The PDF contains numerous external links, with several pointing to compromised CMS upload directories and disposable hosting, suggesting a link farm designed to redirect users. The presence of multiple PDF_URI heuristics confirms the intent to lead users to external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://sun-tes.ru/files/file/37779870511.pdf In PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1614635555d148---tinelutabuvakopen.pdfIn PDF document text
    • http://spalovnachemolak.sk/userfiles/file/38114892915.pdfIn PDF document text
    • https://e-motorcycle.tw/upload/emotorcycle/files/toremiroxinidedunanivebod.pdfIn PDF document text
    • https://ascii.tn/web/cgi/file/5111941686.pdfIn PDF document text
    • http://www.naraihillgolf.com/admin/userfiles/file/97703741902.pdfIn PDF document text
    • http://langmypham.com/luutru/files/21466602215.pdfIn PDF document text
    • http://bukharaalpharetta.com/sites/default/files/file/87736812124.pdfIn PDF document text
    • http://ghibms.com/userfiles/files/zejiwuv.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/ride2i5jf0sa3g2rg3atlc2qq9/mojelokeziropites.pdfIn PDF document text
    • http://nbnjl.com/userfiles/files/79092023760.pdfIn PDF document text
    • https://flcevent.fcu.edu.tw/plugin/ce1/ckfinder/userfiles/files/20210902054954.pdfIn PDF document text
    • http://koszyczarek.pl/userfiles/file/15017398320.pdfIn PDF document text
    • https://penmypoem.com/new/admin/uploadfiles/file/81016981378.pdfIn PDF document text
    • http://drironcat.com/images/file/1316969408.pdfIn PDF document text
    • http://saltokisport.com/uploads/files/gavudekovukomifim.pdfIn PDF document text
    • http://studioscoponi.eu/userfiles/files/kamowosuwojogasune.pdfIn PDF document text
    • http://sibaco.ru/ckfinder/userfiles/files/bilarogivu.pdfIn PDF document text
    • http://l-max.ru/userfiles/file/xejugudedelotiwefow.pdfIn PDF document text
    • https://unitedfightalliance.com/ckfinder/userfiles/files/daruvijogujebinegulukarax.pdfIn PDF document text
    • http://sz-nuoyi.com/Upload/file/2021091206175452086.pdfIn PDF document text
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/o2k78rle4a0fd2mpmju97b6m7o/javukur.pdfIn PDF document text
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/bbaadd456bbfb72820861dcbdde7f830/96261774886.pdfIn PDF document text
    • http://lamekatus.ee/uploads/ckeditor/files/77005895661.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=watch+boiler+room+2000+online+freePDF 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_off0000cf2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF2A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e73c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE73C 19952 bytes
SHA-256: aefbb2ae45e37dd374020a7bee5c3f8ecc908f492e7fa200cde046db696a98fb
font_02_sfnt_off00011bbb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BBB 10808 bytes
SHA-256: a94c78cbe6d7e632dc81e127cf89b2d7edacd55ad2299a72091c5834e5434b1c