Malicious PDF — malware analysis report

Static analysis result for SHA-256 28c412b1e318fe3f…

MALICIOUS

PDF

77.7 KB Created: 2021-09-19 21:31:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: ce1ebcf1024c6e4d31eaba12972cefb8 SHA-1: ce9765c1b16b31bf15dd0a75b851e95cc7a884ae SHA-256: 28c412b1e318fe3f17ec749937066d5413413533eaca6d0341274e69b330240d
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The PDF contains numerous external URIs and is flagged as a link farm on disposable hosting, indicating a malicious intent to redirect users. The embedded JavaScript stream and the ML classifier's high confidence score further support the malicious verdict. ClamAV detection as 'Pdf.Phishing.Trojan' confirms the phishing and trojan nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • 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://coretry.ru/uplcv?utm_term=apk+block+master+for+minecraft+pe PDF link annotation
    • http://challendor.com/fckeditor/upload/file/62627169952.pdfIn PDF document text
    • https://vmgeducationtrust.org/home/vmgedu/public_html/public/userfiles/file/miwawuzis.pdfIn PDF document text
    • https://3rproject.eu/ckfinder/userfiles/files/29598787142.pdfIn PDF document text
    • http://wellogo.in/userfiles/file///72210804023.pdfIn PDF document text
    • http://na-bytecek.cz/UserFiles/File/judonewe.pdfIn PDF document text
    • https://www.winsum.frl/ckfinder/userfiles/files/fuboburixumatadedusenimu.pdfIn PDF document text
    • http://ginzaoakland.com/uploads/files/tafidezemipik.pdfIn PDF document text
    • http://ritadas.in/userfiles/file/daguga.pdfIn PDF document text
    • http://www.tractortools.cz/ckfinder/userfiles/files/wajubexosomuneze.pdfIn PDF document text
    • https://mk-sito.it/uploads/file/bikewujarotirugopunufufak.pdfIn PDF document text
    • https://gtnet-engine.com/ckfinder/userfiles/files/teliliwotivojozopufelime.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-9-16/20210916075408681953.pdfIn PDF document text
    • https://semangkabiji.com/contents/files/57751237964.pdfIn PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/oq5hml6ugvk2p4mkboqkdgpdqn/18387200748.pdfIn PDF document text
    • http://xn--80aagkbrca3apkgkee0a1bi.xn--p1ai/ckfinder/userfiles/files/fanewapuwupazujinanasafu.pdfIn PDF document text
    • https://tttinox.com/upload/userfiles/files/lowowuke.pdfIn PDF document text
    • http://supair-lux.hu/ckfinder/userfiles/files/25837689309.pdfIn PDF document text
    • http://versobrokers.eu/userfiles/files/60811633769.pdfIn PDF document text
    • http://trumoi-khutrung.com/upload/files/losaw.pdfIn PDF document text
    • https://nyirfa.hu/uploads/files/mabonixag.pdfIn PDF document text
    • http://kanalizace-ul.cz/userfiles/file/jotonixisewe.pdfIn PDF document text
    • https://alstar.uz/images/shared/file/90280417639.pdfIn PDF document text
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613a73ba94ced---30819543448.pdfIn PDF document text
    • https://aihr-iadh.org/uploads/FCK_files/file/jatibisitepafojugututal.pdfIn PDF document text
    • http://mackyz7automotive.com/js/upload/files/nosezaxutuzonanepudas.pdfIn PDF document text
    • 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_off0000cc67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC67 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e47e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE47E 10856 bytes
SHA-256: 53cd5daa56d92404ff1fb3b4c49f81efea2860e1664de12ab0277cdd1dbaa0a6
font_02_sfnt_off0000fd54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD54 17012 bytes
SHA-256: e80b261d22f5ca7fdfdf530ca43f1fd81beef923970bb7842fe1f1ec677c570a