Malicious PDF — malware analysis report

Static analysis result for SHA-256 c6c3b5ce0b70766e…

MALICIOUS

PDF

82.3 KB Created: 2021-09-18 19:45:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 073d5bbf3dcb0a323932d72306851866 SHA-1: f90ac8b448cf905658ea3319b6f1491f11cf78a5 SHA-256: c6c3b5ce0b70766e83653c7bef21a43918c3fd1cee880a463775384825885a0c
156 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed for malicious redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The file's structure and numerous external links align with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.
  • 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://krisoc.ru/uplcv?utm_term=galaxy+s8+screen+size+pixels PDF link annotation
    • https://es21sys.com/userfiles/file/nevebodofapaziregemutu.pdfIn PDF document text
    • https://bccphil.paramedix.biz/uploadfiles/file/11153584884.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/9sbf2ukuovp0tkm4ege00pkrf6/gekubu.pdfIn PDF document text
    • http://transbur.ru/admin/ckfinder/userfiles/files/57498354224.pdfIn PDF document text
    • http://signauction.net/userfiles/file/kufakexukaravebiwil.pdfIn PDF document text
    • http://johnmarzillier.com/ckfinder/userfiles/files/37181426277.pdfIn PDF document text
    • https://www.khaosanpools.org/ckfinder/userfiles/files/12271173776.pdfIn PDF document text
    • http://3dprofi.net/images/uploads/file/25144410517.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/161313509968bd---vapexisasesima.pdfIn PDF document text
    • https://kolkatanagariksammelan.org/ckfinder/userfiles/files/julupako.pdfIn PDF document text
    • https://cornwallstaffagency.com/userfiles/file/tijemafozajidet.pdfIn PDF document text
    • https://bushregenerators.com/userfiles/files/zoxamasepisodavuviximed.pdfIn PDF document text
    • http://avvocato-callegaro.it/public/file/98327020751.pdfIn PDF document text
    • http://lixupeng.com/uploads/files/20651562744.pdfIn PDF document text
    • https://merlak.ru/userfiles/file/nimofugewopibosidutunep.pdfIn PDF document text
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614232f466ad4---6405091562.pdfIn PDF document text
    • https://accuratesearch.com/userfiles/file/89083051772.pdfIn PDF document text
    • http://ozkayalartrans.com/userfiles/file/barugiwewobateju.pdfIn PDF document text
    • https://rosenstein.lu/userfiles/files/xerid.pdfIn PDF document text
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16140973da9d76---17646983101.pdfIn PDF document text
    • https://sbsoftware.ro/admin/userfiles/file/80247250458.pdfIn PDF document text
    • http://ekhoron21.mn/uploads/files/6966889865.pdfIn PDF document text
    • http://irodori.kir.jp/files/file/zavanuseferuboki.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_off0000dd4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD4B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f55d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF55D 17716 bytes
SHA-256: 37f6d28610e1cb4e58721f7293dd3a3dd6bb5e2ce492d3f9ca3b3b5ad8590826
font_02_sfnt_off00012303.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12303 10672 bytes
SHA-256: 08476be7592e61415b5e1a734ca70c0228f5fac58019bb678bd861bd9d39c060