Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b1de80a0cce0c1d…

MALICIOUS

PDF

75.8 KB Created: 2021-09-11 11:54:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 0091c52395f64d88fb43560727c6a95e SHA-1: 191d40ee4907117bd2a96a1b96e67bd1ec5c7b60 SHA-256: 4b1de80a0cce0c1d78574a8412a574940137337d587dbd20cadcc69e519fe3f8
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains embedded JavaScript, which is often used to exploit PDF vulnerabilities or redirect users. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a large number of links pointing to potentially disposable domains, suggesting a phishing or spamming operation. The embedded JavaScript likely serves to initiate a malicious action, such as downloading a secondary payload or redirecting to a phishing site.

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://giant-nano.com/app/webroot/userfiles/files/dewonubazurifafevopexe.pdf In PDF document text
    • http://bbfederico2.net/userfiles/file/savunusokebufada.pdfIn PDF document text
    • http://iltorg.ru/upload/file/xerojibum.pdfIn PDF document text
    • https://dmitrovka-zn.ru/admin/ckfinder/userfiles/files/zuvijigiwojuniwamanow.pdfIn PDF document text
    • https://anandalaya.in/resources/file/85802797316.pdfIn PDF document text
    • http://hjhchem.com/upload/files/9063673398.pdfIn PDF document text
    • http://lamorenj.com/userfiles/file/81253365551.pdfIn PDF document text
    • https://sandp-engineering.com/ckfinder/userfiles/files/zuxulijeluni.pdfIn PDF document text
    • http://glovimex.com/uploads/ckfinder/files/26605185988.pdfIn PDF document text
    • https://svetplus.com/userfiles/files/28069555764.pdfIn PDF document text
    • http://vetcasatenovo.it/userfiles/files/9734526169.pdfIn PDF document text
    • https://fullmagicweekend.com/ckfinder/userfiles/files/nokunesupe.pdfIn PDF document text
    • http://ilturismoinitalia.it/userfiles/files/zuvosupagorozirerusu.pdfIn PDF document text
    • https://www.habitat-morvan.fr/ckfinder/userfiles/files/53199426816.pdfIn PDF document text
    • http://innovatepc.com/userfiles/file/57435180564.pdfIn PDF document text
    • http://nassagroup.org/app/webroot/js/ckfinder/userfiles/files/48340040835.pdfIn PDF document text
    • http://scbczy.cn/up_files/file/20210909_031424.pdfIn PDF document text
    • http://dayuntang.com/assets/uploads/ckedit/files/20210905090343.pdfIn PDF document text
    • http://odra.cycling-recycling.eu/imgturysta/files/54794644064.pdfIn PDF document text
    • http://zopos.zohukum.com/ckfinder/userfiles/files/65674118935.pdfIn PDF document text
    • https://cosmeticdermatologymiamibeach.com/uploads/data/files/75471676984.pdfIn PDF document text
    • http://assushop.com/userfiles/assushop.com/file/51414852241.pdfIn PDF document text
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/08d95b2cf3d383e7c8d55d62d7590ae4/58428763354.pdfIn PDF document text
    • https://www.peltonfell.org.uk/ckfinder/userfiles/files/movopijuzekevodalabumis.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=international+law+malcolm+shawPDF 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_off0000c479.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC479 17320 bytes
SHA-256: 75460219f4d88d3d9d4d19a225514b87e666090f9136b474e8aae95035c6c21e
font_01_sfnt_off0000f169.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF169 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010980.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10980 10532 bytes
SHA-256: 2f3a713ee7eecdd41b1caf1b0a6842367041afd0094f7da4972536c328d1659f