Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f72673871db3247…

MALICIOUS

PDF

68.3 KB Created: 2021-10-02 10:57:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 122505b22891d780cbfbd55612943387 SHA-1: ef975c96adcf0a6fe2701f17972805a8569bfa62 SHA-256: 5f72673871db32479cb46a903e5be452366f571da1dfff3f91e51f6b48bcd04a
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier, containing embedded JavaScript. The PDF also functions as a link farm with numerous external URLs, many pointing to disposable hosting, indicating a likely phishing or redirection scheme. The embedded JavaScript is a strong indicator of malicious intent, potentially to download further payloads or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://postelezmasivu-liberec.cz/ckfinder/userfiles/files/99652462835.pdf In PDF document text
    • http://laptopcuhaiphong.vn/upload/files/vipeb.pdfIn PDF document text
    • http://mistral-paints.cz/userfiles/files/29974074322.pdfIn PDF document text
    • https://tgvl.in/uploads/fck/files/13534460597.pdfIn PDF document text
    • https://mimpishio2.com/contents/files/petojojudazi.pdfIn PDF document text
    • http://dailymaydemtien.com/userfiles/files/bodakogadufumemonividovum.pdfIn PDF document text
    • https://www.gurgy.net/ckfinder/userfiles/files/61974032552.pdfIn PDF document text
    • https://ustunbilgisayar.com/userfiles/files/zusatavapufetegil.pdfIn PDF document text
    • https://stabiactiv.com/userfiles/file/65920538806.pdfIn PDF document text
    • https://www.mftelhas.com.br/adm/Editor/ckfinder/userfiles/files/42736058579.pdfIn PDF document text
    • http://hoigolfbinhthuan.com/users/files/51397848665.pdfIn PDF document text
    • http://zjbfjt.com/upload/files/viwekor.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/b410c6cbbf2597c16af9abe5a04d0549/gesamoxetogudenuwarufoma.pdfIn PDF document text
    • http://dreamsurgerycn.com/ckupload/files/10109897253.pdfIn PDF document text
    • http://cbstav.cz/file/raxev.pdfIn PDF document text
    • http://bienbao.net/uploads/files/55041196095.pdfIn PDF document text
    • https://epm.jot-solutions.com/files/25984334717.pdfIn PDF document text
    • http://winterwonderlandzundert.nl/uploadimages/files/fitaluzuravupowiba.pdfIn PDF document text
    • http://tms-technology.com/ckfinder/userfiles/files/86592350953.pdfIn PDF document text
    • http://shiny-baby.com/fileimage/file/47016847671.pdfIn PDF document text
    • https://www.rongoldmanlaw.com/system/js/back/ckfinder/userfiles/files/guwilemeb.pdfIn PDF document text
    • http://www.findvoters.com/userfiles/file/94340795557.pdfIn PDF document text
    • https://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/687cd46bd28ba2f743c88e895494fcb4/dakugun.pdfIn PDF document text
    • http://minipit.com/data/files/65111559215.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=installed+gfci+no+powerPDF 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_off0000ae78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE78 15016 bytes
SHA-256: 4b38b702cfe82afcd9859c663e5ac56a89ca7d82908095c5c0b7a973d0cff880
font_01_sfnt_off0000d2e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000eaf8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAF8 10832 bytes
SHA-256: 322d146cb4c7cb69bcd8a1bf123892cfd47f155ed6e631744826a840f419c6ff