Malicious PDF — malware analysis report

Static analysis result for SHA-256 2cd6b3a495fb5bcb…

MALICIOUS

PDF

78.9 KB Created: 2021-09-16 23:48:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: eb950be02d9920e888670b4f1c6eea81 SHA-1: f45cd1c98374961c75bbe74bb3d0074941ef36dc SHA-256: 2cd6b3a495fb5bcbb4c467490a7c416a2075acd09cb05bf75d7ccb1737d8f719
174 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and multiple links to external websites, with one specifically identified as an algorithmically generated URL. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a non-clustered link farm on disposable hosting, suggesting a malicious intent to distribute further payloads or conduct phishing. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://stotex.rs/files/54054138688.pdf In PDF document text
    • http://linker-apps.com/files/37625729330.pdfIn PDF document text
    • http://trumoi-khutrung.com/upload/files/duvuvoxiluzabeg.pdfIn PDF document text
    • https://pacientes.quiroser.com/UserFilesQUI/file/fifitifabotowusukifezaga.pdfIn PDF document text
    • http://pokrowce-ochronne.pl/Upload/file/51870150049.pdfIn PDF document text
    • http://euro-ex.com/images/blog/file/jepuzoniliduwosu.pdfIn PDF document text
    • http://metalltechnik-kutschi.at/30647600235.pdfIn PDF document text
    • http://xhzhengli.com/upload/40547589190.pdfIn PDF document text
    • http://hitecds.com/userfiles/file/85199897443.pdfIn PDF document text
    • http://planbmedia.hu/files/sizesujaradojas.pdfIn PDF document text
    • http://zhengfutz.com/v15/Upload/file/202198046224931.pdfIn PDF document text
    • http://bet-balance.com/userfiles/file/netozatasazulufibe.pdfIn PDF document text
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/161412393cb724---78485362646.pdfIn PDF document text
    • https://soudureornementalelauziere.com/upload/editor/file/74901078986.pdfIn PDF document text
    • http://bmfjhjk.friend-match.com/upload/files/wuraku.pdfIn PDF document text
    • http://hitecds.com/userfiles/file/50958158013.pdfIn PDF document text
    • http://sooam.com/files/fckeditor/file/39038851561346efff41b1.pdfIn PDF document text
    • http://laulumaja.fi/ckfinder/userfiles/files/bubafewiruredulifebubudi.pdfIn PDF document text
    • http://funkyspa.net/ckfinder/userfiles/files/sepuvanujosovef.pdfIn PDF document text
    • http://ambulatorioveterinariosantanna.eu/userfiles/files/dutetudatewonulegojoduxos.pdfIn PDF document text
    • http://conservativista.com/js/ckfinder/userfiles/files/44203373985.pdfIn PDF document text
    • https://baxsporthorses.com/userfiles/file/5974717023.pdfIn PDF document text
    • https://mediaget.ru/userfiles/files/lipukuwewejodikera.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=how+to+save+vcf+contacts+in+androidPDF 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_off0000d123.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD123 17188 bytes
SHA-256: a8e95e13ad85cbadb5086bdb42213930fc39dd5a0ae20f7fb104529d1efbefaa
font_01_sfnt_off0000fd7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD7B 10568 bytes
SHA-256: ce31578b7a5242c2320d4199f2f814cf78bfd970bf7635ed033ecd0b9e93f858
font_02_sfnt_off000115c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115C1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1