Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc8d1a00953109e1…

MALICIOUS

PDF

83.3 KB Created: 2021-09-19 22:05:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: cb2e47b11d361f570eb8d57d4465a7c5 SHA-1: 86b939172c9dfecad0360fed7bbce2e44af1b0e3 SHA-256: dc8d1a00953109e1d603ef658c74571215f586f992dabaad2a90349dd504cfa5
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, indicating malicious intent. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document is designed to host many links on disposable domains, likely to obscure malicious destinations. The ML classifier and ClamAV detection strongly support a malicious verdict, with the embedded JavaScript likely facilitating the redirection to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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=always+on+display+premium+apk PDF link annotation
    • http://corporatiegids.nl/uploads/files/wukonegedijakurem.pdfIn PDF document text
    • http://vnndt.com/Images_upload/files/45927388598.pdfIn PDF document text
    • https://menu2uplus.com/images/file/rirejizerikukut.pdfIn PDF document text
    • http://needychild.org/ckfinder/userfiles/files/xonawagum.pdfIn PDF document text
    • http://wieswioska.pl/userfiles/file/78098167731.pdfIn PDF document text
    • http://www.palmettoexpresslanes.com/system/js/back/ckfinder/userfiles/files/33936133771.pdfIn PDF document text
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/10188f21a5a2adfc0252b58c8dee383b/40708689959.pdfIn PDF document text
    • http://oreoltour.ru/sites/default/files/file/38287271215.pdfIn PDF document text
    • https://8foro.exceltur.org/exceltur_nuevo/ckfinder/userfiles/files/fejinakoraronolonimoren.pdfIn PDF document text
    • http://ucinnovation.ru/admin/ckfinder/userfiles/files/gudoxadibej.pdfIn PDF document text
    • http://pijntherapie.be/uploads/files/lulavelararudadanato.pdfIn PDF document text
    • http://defhjdrjioo.friend-match.com/upload/files/bijepigunobaxader.pdfIn PDF document text
    • http://goodtraefarm.com/ckupload/files/soguduwokiso.pdfIn PDF document text
    • https://lensmam.com/userfiles/file/daxowadegesinorat.pdfIn PDF document text
    • https://www.a2zmedical.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16131bd55ae254---2014230680.pdfIn PDF document text
    • http://abwmechanicsville.com/uploads/files/wogafobupegetov.pdfIn PDF document text
    • http://fitviewer.info/files/file/13221416609.pdfIn PDF document text
    • http://parbatsamajjapan.com/img/files/files/molawikojatudifaxipib.pdfIn PDF document text
    • http://jmlukanich.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/pugemenivun.pdfIn PDF document text
    • http://jowinbio.com/upload/files/202109021447533651.pdfIn PDF document text
    • https://ctcitsupport.com/media/files/kujuzilabuzezi.pdfIn PDF document text
    • http://centralcogtc.com/uploads/file/46940199943.pdfIn PDF document text
    • https://airxps.com/userfiles/files/55679654561.pdfIn PDF document text
    • http://animalscipublisher.com/files/upfiles/file/kifajururagudedelijirur.pdfIn PDF document text
    • http://ibrahimalsada.com/pics/file/17981011492.pdfIn PDF document text
    • http://polyacer-ecp.com/userfiles/files/20210908_043027.pdfIn PDF document text
    • http://fujieshubao.com/zk/UploadFile/file/2021090619584073499.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_off0000dd7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD7F 18532 bytes
SHA-256: a214de4c6c22650144c456ab9b8831908ef260e945f02be6ede79bdb67ef82b3
font_01_sfnt_off00010dcf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DCF 10828 bytes
SHA-256: 735c98047263fe1c6ebad4c07bed3aebe21688d204dd0373ba444808ab97f8c6
font_02_sfnt_off000126da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126DA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1