Malicious PDF — malware analysis report

Static analysis result for SHA-256 c9cb0c237b8e26f7…

MALICIOUS

PDF

69.5 KB Created: 2021-09-28 16:27:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: aac185cb98744730833bd2a14401ecbd SHA-1: 3aed8ad72aa0472a9169bc9af88de9e1d5ae9710 SHA-256: c9cb0c237b8e26f74c55c79e08bd2bc08f0ed4dfc31799a6217ce83a1cd18cc9
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to disposable domains and are structured as link farms. This suggests the primary purpose is to redirect users to malicious content or phishing sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for distributing further malware or facilitating phishing campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://queure.ru/uplcv?utm_term=data+structures+and+algorithms+made+easy+by+narasimha+karumanchi+pdf PDF link annotation
    • https://htapigroup3.com/contents/files/15686999235.pdfIn PDF document text
    • http://kayapalinakliyat.net/file/jolix.pdfIn PDF document text
    • https://learn-atdi.com/uploads/files/wurametapof.pdfIn PDF document text
    • http://ajeah-intl.org/fck_image/file/xobexujivezigemotuzukab.pdfIn PDF document text
    • http://hfengly.dk/skoleportalen/userfiles/file/57085653290.pdfIn PDF document text
    • http://insei.eu/userfiles/files/33473398094.pdfIn PDF document text
    • http://superazs.ru/images/news/file/68330192042.pdfIn PDF document text
    • http://fmafirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/nagev.pdfIn PDF document text
    • http://fishtech.org/uploads/userfiles/file/file/46722180055.pdfIn PDF document text
    • https://mimpidia.com/contents/files/fevanezivupek.pdfIn PDF document text
    • https://childprotectionindia.com/lexcyberia/userfiles/files/nitesisukanefulim.pdfIn PDF document text
    • http://studioagm.it/userfiles/files/98586373631.pdfIn PDF document text
    • http://yoron.net/up/files/44973113636.pdfIn PDF document text
    • http://nextlab-semi.com/files/fckeditor/file/29899273630.pdfIn PDF document text
    • http://secureyun.cn/uploadfile/file///2021091614131581.pdfIn PDF document text
    • http://thanuyentea.com/ckfinder/userfiles/files/sipitutuxitef.pdfIn PDF document text
    • http://careerpathrecruitment.com/swapscan/app/webroot/js/ckfinder/userfiles/files/jadanifixirejis.pdfIn PDF document text
    • http://coaching-scolaire.net/userfiles/file/lufovetokejubinojexoge.pdfIn PDF document text
    • http://www.physedu.in/newsite/userfiles/files/22947547390.pdfIn PDF document text
    • http://bukharageorgia.com/sites/default/files/file/42288861412.pdfIn PDF document text
    • http://mineraux-et-lithotherapie.fr/ckeditor/upload/files/54304275492.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/ej5k3cede6ln3acs8qm76vgcu4/9179551284.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_off0000ad86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAD86 15776 bytes
SHA-256: 7a5880386a6d1e5b6dd789fcf3600c2355b8409453808f514432e40d73d57e15
font_01_sfnt_off0000d587.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD587 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ed9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED9E 11512 bytes
SHA-256: c0665390947e45689600ba3abe932dde619348cdb3dd39ca596104bd09ab236e