Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b5f78fe7a535f3b…

MALICIOUS

PDF

79.3 KB Created: 2021-09-10 13:18:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3a4fc4e967e924f9c585aa2fbdd8f348 SHA-1: af70e30b3e8da37e64e376381c9dd58ae2ee8954 SHA-256: 8b5f78fe7a535f3b387ae2484fddaf85f9e99498b4b1152a79210c9f26db4210
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which are hosted on potentially compromised or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. The presence of embedded JavaScript points to its use in executing malicious actions within the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://callmarkinvestments.fortunekenya.com/callmark/files/tebuvupadufutu.pdf In PDF document text
    • http://spostojow.pl/userfiles/file/sajiwabipi.pdfIn PDF document text
    • https://consultemergingmarkets.cubsindia.com/files/juzodadixozimutamekumupe.pdfIn PDF document text
    • http://epwuae.com/userfiles/file/97593853246.pdfIn PDF document text
    • http://kpghomerepairs.com/uploads/image/files/60057981250.pdfIn PDF document text
    • https://orig-shop-gsm.ro/ckfinder/userfiles/files/buwupejugosezalisefa.pdfIn PDF document text
    • https://adikkedua.com/contents/files/6471997908.pdfIn PDF document text
    • https://chungangroup.com/uploads/files/202109060645269844.pdfIn PDF document text
    • http://petraifevronii.ru/ckfinder/userfiles/files/zovogirorigulun.pdfIn PDF document text
    • https://swalaya.in/userfiles/file/40380842524.pdfIn PDF document text
    • http://artattack-concerts.de/files/file/97646243829.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/161318fd0c5842---55706430665.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/161300962e05fa---gadebix.pdfIn PDF document text
    • https://suacuacuontoanphat.com/upload/files/60310309496.pdfIn PDF document text
    • https://apz-arte.com/ckfinder/userfiles/files/xodogiritetenukerorujufu.pdfIn PDF document text
    • http://uran-berlin.com/userfiles/file/11371933566.pdfIn PDF document text
    • https://orig-shop-gsm.ro/ckfinder/userfiles/files/dasujinifegavalanal.pdfIn PDF document text
    • https://bd-sokolovska.eu/userfiles/file/zutexiradapuka.pdfIn PDF document text
    • https://sleepthai.com/piceditor/file/37223002746.pdfIn PDF document text
    • http://chuaphucluong.com/uploads/image/files/61566603244.pdfIn PDF document text
    • https://autosaloncenter.com/uploads/file/54237490421.pdfIn PDF document text
    • http://garageanything.com/js/upload/files/fawedamezojagogete.pdfIn PDF document text
    • https://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ff6d6e4ad4---rimazedamigez.pdfIn PDF document text
    • https://masterpieces-mallorca.com/wp-content/plugins/super-forms/uploads/php/files/eed831b637d4eb942b3460c8423cf5ef/wabotomugifikadalavozige.pdfIn PDF document text
    • http://women-for-marriage.com/ckfinder/userfiles/files/kigoxijujuxerorunologotu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=go+to+talkbackPDF 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_off0000d605.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD605 16872 bytes
SHA-256: b6918b603fdc4dd21d22b01179fa1379bcb0e25fde55a3b6c06fcaa6ffd575cd
font_01_sfnt_off0001019f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1019F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000119b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119B5 9900 bytes
SHA-256: 7ab209e98f681e2ae1b6ee56169dffdad2b8fd3b3d0702fbd1d34ac64abbd1b4