Malicious PDF — malware analysis report

Static analysis result for SHA-256 ee51e9085f8dc102…

MALICIOUS

PDF

78.1 KB Created: 2021-09-05 05:50:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 5d4b4efef480f26baecc8def4e05123c SHA-1: b7e0683bd15de70d4f76f6121a391ed7d1c83b38 SHA-256: ee51e9085f8dc102ab50df31b0091983001f393d770c31aa58b7671b5e113516
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised websites or disposable hosting, indicative of a link farm. Heuristics flag it as a potential phishing or malicious PDF, with ClamAV detecting it as 'Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0'. The ML classifier also strongly flagged it as malicious. The primary attack pattern appears to be leveraging these links for malicious purposes, likely initial access via spearphishing.

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://beijingteye.com/upload/files/10517371795.pdf In PDF document text
    • http://gourmethousemacau.com/UploadFilesfile///wopewo.pdfIn PDF document text
    • http://fogathajtohirek.hu/fckfiles/file/45398650145.pdfIn PDF document text
    • https://nhadatonline24h.com/Images_upload/files/pejirejojukoxakurowomo.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608b4b46ad4fb---pasoxabokaxafebolodakok.pdfIn PDF document text
    • http://agendatourvietnam.com/hinhanh/file/18917185807.pdfIn PDF document text
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/8ddncbgcsre0hht63uia2a02i5/kominerajidobe.pdfIn PDF document text
    • https://www.beadvised.co.uk/wp-content/plugins/super-forms/uploads/php/files/30ff55b1cae2ddf0c0818c66c9da3b8b/72255442433.pdfIn PDF document text
    • https://mszukam.pl/dat//file/4697296380.pdfIn PDF document text
    • https://www.finestkindcharter.com/wp-content/plugins/formcraft/file-upload/server/content/files/160860e9a6b720---74420803167.pdfIn PDF document text
    • http://jumpinfit.it/userfiles/files/xemobovaz.pdfIn PDF document text
    • http://www.peopleoftheheath.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfd94b4a6d2---83717017176.pdfIn PDF document text
    • https://festivaldelmaridaje.com/sgi_userfiles/userfiles/files/936810925.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fb6d9db568---samaxawajese.pdfIn PDF document text
    • http://pratiklinik.com/img/userfiles/files/wewot.pdfIn PDF document text
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/20a4149b6418218c07e20d3723ff79a3/6158544431.pdfIn PDF document text
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/bf69151965a4a120584b0f7ed1fd7ad0/94122394006.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/160ad74c597fef---71087932648.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a083b4153af---93724517509.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/677cf51772a167e9a26da5ff1a45a5b2/rulopivepuvafometemub.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/f70215216929928f63d44f62f477b657/74028511716.pdfIn PDF document text
    • http://wellgroup.cz/UserFiles/File/23652846557.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16085e5cee6d4d---78887089858.pdfIn PDF document text
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/16104f499352eb---77627576116.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=roots+prefixes+and+suffixes+worksheetsPDF 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_off0000ccb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCB3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e4ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4CA 10972 bytes
SHA-256: db92fde1532b8ad1a8590b077b52b85ca395e8f06ea571c67ab5584bfa378c02
font_02_sfnt_off0000fe4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE4C 17620 bytes
SHA-256: 684a5bb2af8015f78a628ca6c7b2f04bca7d8c108e950907c8361c4f64d63a5d