Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4ea49c3073f30a2…

MALICIOUS

PDF

85.9 KB Created: 2021-06-30 07:23:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 87625b8359b57cc5f66211cf32fee31b SHA-1: c3497bacb0144ff8608f5d607647fdb3173cdf01 SHA-256: b4ea49c3073f30a211bf0807267763a828db9f9b6adc424f1ee33360530ab465
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous external links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, lacking clear user-facing content but containing embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://archism.ru/uplcv?utm_term=how+to+save+excel+graph+as+pdf
    • https://alianzatours.com/imagenes/file/nejeporujudu.pdf
    • http://zonazero.es/userfiles/file/sizibavakodujabe.pdf
    • https://agentcctv.com/userfiles/file/96859483190.pdf
    • http://nutricion-intravenosa.com/wp-content/plugins/super-forms/uploads/php/files/9b7a94f60630201dcabf7a5d8e8df7e5/83708899809.pdf
    • https://wfca-czech.cz/temp/userfiles/files/31948976437.pdf
    • https://123natura.com/stockages/files/92236378751.pdf
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/160d762260807b---mudaxukodutulowirinuf.pdf
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/edc0dfe7090c593f5f81301e61641188/vowofo.pdf
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d9917cc5064---63522123584.pdf
    • http://baohanhranghm.com/upload/img/files/25723646028.pdf
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/983c451ade5e10e06aebdc5672a1b905/29330972345.pdf
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/2fa8c3590f49c97b9200018dae75e115/26549042815.pdf
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16090903666005---jogidoxesoganivepekasoj.pdf
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/160ab089a5b6dc---93077237653.pdf
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/dbdef99c6625bb7a1183fa5afa70f202/rugefolifinobaburejukijo.pdf
    • https://aulacvn.com/upload/fck/file/1082585778.pdf
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/b0b6c25e530eefa7686c3d339a68b46d/zotebitub.pdf
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076e0b7019e2---vimegojot.pdf
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/160885e6845b2f---gedirib.pdf
    • http://mfcwestenkwartier.nl/beta/userfiles/file/34303556649.pdf
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb64923642---daviwoguzobamebagadozi.pdf
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b7a7c215cc7---timigirapasidisulafux.pdf
    • http://ourhkg.com/UPFILE/userfiles/files/dumuwijazokur.pdf
    • http://smflow.in/admin/uploads/file/vomiwogenadojub.pdf
    • https://ancoraeducacion.com/images/59782931153.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_off0000ebdd.bin
72c560647a968029572a0cf1aceab87c767193e7058cc29a915b9c488e9d2fae
pdf-font-stream PDF embedded font (sfnt) at offset 0xEBDD 10948 bytes
font_01_sfnt_off0001053b.bin
2e6bf2823ed905adc590193d79a35ca42ec3505a4e6e07b2e6a990902eec1855
pdf-font-stream PDF embedded font (sfnt) at offset 0x1053B 17272 bytes
font_02_sfnt_off0001322a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1322A 16792 bytes