Malicious PDF — malware analysis report

Static analysis result for SHA-256 3661c9d4fd0609b6…

MALICIOUS

PDF

74.6 KB Created: 2021-09-18 22:07:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e6193782f3b1b235480b34ec55b9e159 SHA-1: 1de8619d1e0e803ed2c71413ba3caf5d9e6b4080 SHA-256: 3661c9d4fd0609b69dc706661ae10c2b8577137bef0946256cb8dda9c2626337
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. It contains embedded JavaScript, indicating an attempt to execute code within the PDF viewer. The PDF also includes numerous external URIs, many of which point to disposable domains, suggesting a link farm or redirection mechanism to deliver a malicious payload or phish for credentials. The presence of embedded JavaScript and external links strongly suggests an attack pattern involving user interaction to navigate to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • 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://confeccionesruiz.cl/UserFiles/File/21288575493.pdf In PDF document text
    • http://imhyuk.com/imhyukeditor/userfile/file/vafovivorunelolotolud.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/161416baa4a50b---86273154111.pdfIn PDF document text
    • http://duhochoangthanh.com/upload/files/tevifux.pdfIn PDF document text
    • https://maharajganjtimes.com/assets/ckfinder/core/connector/php/uploads/files/daluxufogizuvebugas.pdfIn PDF document text
    • http://reversetheclocknow.com/ckfinder/userfiles/files/73491855899.pdfIn PDF document text
    • https://clinicamanila.com/ckfinder/userfiles/files/pijuvininaxujodusab.pdfIn PDF document text
    • https://pfollowers.com/ci/userfiles/files/dujokofafobimotunejar.pdfIn PDF document text
    • http://paulbwatkinslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/98253224230.pdfIn PDF document text
    • https://renebeumer.nl/userfiles/file/xurewot.pdfIn PDF document text
    • http://aktifbant.com/resimler/files/nipofijiniw.pdfIn PDF document text
    • http://verypool.cn/images/upload/File/gibipulimekesoguviros.pdfIn PDF document text
    • http://ozkayalarlojistik.com/userfiles/file/lomekegupulebekesuto.pdfIn PDF document text
    • https://ezgoe.com/10005001208290177/ckfinder/userfiles/files/vawufetadebaw.pdfIn PDF document text
    • https://promenade-perpignan.com/userfiles/file/jadufupo.pdfIn PDF document text
    • http://cx-gl.hu/images/files/vemumawave.pdfIn PDF document text
    • http://corising.info/sa_upload/userfiles/file/20210914181455.pdfIn PDF document text
    • https://pchome.uzai.ca/upload/files/pijimatowofizigevowa.pdfIn PDF document text
    • http://thementalhealthadvocates.org/files/userfiles/file/57979289854.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bcead0ef01---sosupejat.pdfIn PDF document text
    • http://nano-vip.com/ckfinder/userfiles/files/22459254258.pdfIn PDF document text
    • http://daisin1977.com/js/upload/files/konuvanejewazodix.pdfIn PDF document text
    • http://alothongtin.com/upload/FCK/file/timojixoruvopulafagov.pdfIn PDF document text
    • http://crabandclaw.com/uploads/files/tilufidube.pdfIn PDF document text
    • https://cli-kh.com/uploads/files/202109051325134750.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=air+on+g+string+violin+pdfPDF 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_off0000c2ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2AC 10424 bytes
SHA-256: 2f822b6ecfcd28b0214d65a51e3dded3ca818b4f994ae91b6caf51c2310797b6
font_01_sfnt_off0000da37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA37 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f249.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF249 16624 bytes
SHA-256: 2a346227202ee74baf66b16a599818404a8ad9fc161fb9a1f18955a3be830e81