Malicious PDF — malware analysis report

Static analysis result for SHA-256 c3b8c80c27f7c965…

MALICIOUS

PDF

82.2 KB Created: 2021-09-11 02:13:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 3bab3fa59be12a2231e5b514f7dafbed SHA-1: aa243063665ffaac115435fa06f3a7a699c9e383 SHA-256: c3b8c80c27f7c9656e9de9837c604c7f3bc2eb3058bb7fbead5e314d8ed13664
154 Risk Score

Malware Insights

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

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. The PDF also contains numerous external URIs, including one pointing to a raw IP address, suggesting it is part of a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely involving the exploitation of PDF vulnerabilities to deliver a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://krisoc.ru/uplcv?utm_term=fundamentals+of+solid+state+physics+pdf PDF link annotation
    • http://vividconcept.in/userfiles/file/30578494228.pdfIn PDF document text
    • https://amigo-shop.105h.net/upload/files/80556167906.pdfIn PDF document text
    • http://rsst77.ru/upload/files/27563281880.pdfIn PDF document text
    • http://w3-japan.com/js/upload/files/bupabaridadigakupowetukad.pdfIn PDF document text
    • http://luxcottage.ru/stroykamen/userfiles/files/22585883973.pdfIn PDF document text
    • http://evo-models.com/uploads/userfiles/files/xuwiro.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/161300a5b13e18---58426844725.pdfIn PDF document text
    • https://matkinhantai.com/luutru/files/saxoleketetasa.pdfIn PDF document text
    • http://huichem.com/ckfinder/userfiles/files/vowukiwekili.pdfIn PDF document text
    • https://tennis-samara.ru/img/file/tibatokiwomuj.pdfIn PDF document text
    • https://icoachyou.biz/images/ckeditor/files/16459746235.pdfIn PDF document text
    • http://ourconn.com/userfiles/file/202109101817066522.pdfIn PDF document text
    • http://rimini-portal.de/bilderarchiv/file/dopedit.pdfIn PDF document text
    • https://lotte-ppta.com/beta/assets/file/namadox.pdfIn PDF document text
    • http://hyundaidongdo3s.com/images/files/69909726860.pdfIn PDF document text
    • http://104.156.58.56/~web2inbox/wp-content/plugins/formcraft/file-upload/server/content/files/1612f882ff1647---sobisesekegejaxolexel.pdfPDF link annotation
    • https://eurochen.com/UpFiles/WebEditorFiles/file/60960010731.pdfIn PDF document text
    • https://gtijsr.com/userfiles/file/gexiluwubujujefonuvival.pdfIn PDF document text
    • https://ev-owners.jp/userfiles/files/7622292702.pdfIn PDF document text
    • http://realcomfort.ru/content/upload/file/gutemezitewum.pdfIn PDF document text
    • https://www.lire-les-notes.com/ckfinder/userfiles/files/22486463420.pdfIn PDF document text
    • http://www.pibmg.com.br/ckfinder/userfiles/files/files/25509440805.pdfIn PDF document text
    • http://sethhukumchandschool.com/userfiles/file/jenewotaruzejufojuwim.pdfIn PDF document text
    • https://kaktutzhit.by/uploads/files/57207937883.pdfIn PDF document text
    • http://chinalabware.ru/d/files/pisilabutasironazamopibog.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_off0000d7df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7DF 18828 bytes
SHA-256: f879209040a66a9d59c7dd2f4b2684876f88a7626ce051814e07dbaad3df30e5
font_01_sfnt_off00010956.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10956 10976 bytes
SHA-256: 9001eaa6ddbb3f6434d7595dc4843caf4f4ac39366e6052c9b3f6fa58057495a
font_02_sfnt_off000122a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122A5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1