Malicious PDF — malware analysis report

Static analysis result for SHA-256 3d66874552b6698d…

MALICIOUS

PDF

73.0 KB Created: 2021-09-12 22:55:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 51825b3c705fd964dd372fb75536adbb SHA-1: 586c1c216f6bbef28173e552093f246754c64ed3 SHA-256: 3d66874552b6698d48c31348a9c289092108af87e2bb81249805e86e418e3494
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or are part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. The file's structure as a link farm suggests it's intended to lure users to external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://zvezda-rostov.ru/ckfinder/userfiles/files/navamejakarirem.pdf
    • http://inter-travel.hu/_user/file/11780756241.pdf
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/52drcqe0ek6e2em93afrqkebgr/45037838619.pdf
    • http://thebeautyofdesign.nl/ckfinder/userfiles/files/dipaguvazorerefewelenizu.pdf
    • http://audiencefertilization.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/sijivuxive.pdf
    • http://myflora888.com/ck_files/files/wurasazifodogufozojem.pdf
    • https://volnynaklad.cz/data/file/39586470052.pdf
    • http://www.findvoters.com/userfiles/file/11304183558.pdf
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/79fcc6c68c5f03e536a3e372772564d6/30345873844.pdf
    • http://urbanelect.com/userfiles/file/kirizubepulakagap.pdf
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cb1361ec42---87287306406.pdf
    • https://lifesmart.lifesmart.ro/ckfinder/userfiles/files/tukejubebetejotenatuf.pdf
    • http://sbkf.org/files/files/tefuwosab.pdf
    • http://sudeoksa.com/userfiles/file/20210912085629.pdf
    • https://behagi.eus/files/galeria/files/56174552353.pdf
    • http://aktifbant.com/resimler/files/nipofijiniw.pdf
    • https://geniodelweb.com/file/49972611071.pdf
    • http://nutranghongngoc.com/media/ftp/file/nutixudamofofu.pdf
    • http://primebrokeragetx.com/ckfinder/userfiles/files/dolerilizunomigudedoxekad.pdf
    • http://abogadosaguilar.com/ckfinder/userfiles/files/97537482558.pdf
    • http://nfc.soo.jp/file/zejibasijubikofoziso.pdf
    • http://mail.me.ntou.edu.tw/ckfinder/userfiles/files/20210907_223115.pdf
    • http://kassa.pl/userfiles/file/paramogaguk.pdf
    • https://efficimm.fr/userfiles/files/52355379681.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=c+tutorial+pdf+free+download
    • 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_off0000bb05.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBB05 16792 bytes
font_01_sfnt_off0000d31c.bin
e24cd76555ac598491cba15b582f9587379264ed0b5e6a8a377a333565abfdc2
pdf-font-stream PDF embedded font (sfnt) at offset 0xD31C 10540 bytes
font_02_sfnt_off0000eb4f.bin
89b632528d49109704b832e2f46e642fda7be5437bbe370724dad1b9f6f84a1f
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB4F 16788 bytes