Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3cb363e04c34ea0…

MALICIOUS

PDF

88.3 KB Created: 2021-09-21 21:29:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 82cea0b6a0a4fb2d5dbff7320a6003ec SHA-1: 02fe8b034966e6f983749d470ac094d80e99027e SHA-256: b3cb363e04c34ea09651d4d92db8728b3654a25b115c09c594cac1004bb57647
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. It contains numerous external URIs pointing to various domains, many of which are hosted on disposable or compromised infrastructure, suggesting an attempt to redirect users to malicious content. The presence of embedded JavaScript further supports its malicious intent, likely to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://nomylo.ru/uplcv?utm_term=legend+of+zelda+link+to+the+past
    • http://olgapolyakova.de/files/files/xipemuvutexetu.pdf
    • https://profitaler.com/UserFiles/file/zifokajitomaxijade.pdf
    • https://oxfordjsr.com/userfiles/file/mimusugovoruwefejipuf.pdf
    • http://hublihorse.com/uploads/userfiles/files/zovuwokedujubov.pdf
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161394f8c19d76---48238239888.pdf
    • https://suncables.co/images/file/67382660827.pdf
    • http://taxiluzern.ch/khurasan/userfiles/files/superob.pdf
    • http://files.ibiza-ferien.de/file/wekajuberuz.pdf
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/bk7phcfk1pl2n8gij0lak5r9fd/gifipejaf.pdf
    • https://factorysales.com/userfiles/files/59268682337.pdf
    • https://b2bircruise.travflex.com/bot/ckfinder/uf/files/23906215486.pdf
    • https://kontiko.com/ktkweb3/images/upload/files/64816041282.pdf
    • https://on-call-anatomist.org/ckfinder/userfiles/files/74768543499.pdf
    • http://freeorden.com/media/file/gejunemuxididoxovore.pdf
    • http://stonepigments.com/userfiles/file/48235127432.pdf
    • http://toyotaprius-custom.com/js/upload/files/32129158886.pdf
    • http://naturalmis.com/userfiles/file/jaxozonaranatewexusozo.pdf
    • https://safewatersolutions.in/ckfinder/userfiles/files/55818526490.pdf
    • http://www.ekoforte.com/upload/file/11917937566.pdf
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614547ef6eabf---podomupoto.pdf
    • https://www.colline-eternelle.com/ckfinder/userfiles/files/51034533216.pdf
    • http://ambvet-trefontane.eu/userfiles/files/38242701057.pdf
    • https://songod.vn/uploads/image/files/43479734008.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f5b9.bin
9ce0277cef6ac5a55499b7ce7d6777ab8cefdcd744437c5734ed8acf9d1ecfee
pdf-font-stream PDF embedded font (sfnt) at offset 0xF5B9 10788 bytes
font_01_sfnt_off00010e51.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E51 16792 bytes
font_02_sfnt_off00012663.bin
74e9be65faf87af0210c8cc47e01a7653efb90522992afdd5c223b193d9260ad
pdf-font-stream PDF embedded font (sfnt) at offset 0x12663 17744 bytes