Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbb90d3621e5ebf3…

MALICIOUS

PDF

81.3 KB Created: 2021-07-30 00:37:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8289f459be4b3d13d8241f3fba21d49a SHA-1: 55e159625ea5995978843923c277418d7891b0db SHA-256: cbb90d3621e5ebf3ffab9efdd57213958902e3d42d305aab79a8c3b486d0647d
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file contains embedded JavaScript and numerous external URIs, many of which point to compromised websites or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document is a link farm designed to redirect users, likely to phishing sites or malware downloads. The ML classifier and ClamAV detection strongly suggest malicious intent, with the embedded JavaScript potentially being used to facilitate the download and execution of a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://laborke.ru/uplcv?utm_term=dragonframe+4+serial+number+free
    • https://estigotours.com/wp-content/plugins/super-forms/uploads/php/files/0c1a4ac54c803d790a57d61f80299c6a/10782715868.pdf
    • http://turagent007.ru/userfiles/file/16259866034.pdf
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b76b6ab3f83---sunur.pdf
    • http://sakuragiramenandsushi.com/uploads/files/bixamiranevefozorapakevi.pdf
    • http://plncse.hu/php_data/file/43284399511.pdf
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/6a431b2850a7ed10072df6283a5244a1/popilarovazunoxove.pdf
    • http://centrlita.ru/archive/image/file/97891033605.pdf
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160b22fbe2e302---bugifidosesosimu.pdf
    • https://parquesanalbertohurtado.cl/ckfinder/userfiles/files/loxisixenezogumu.pdf
    • https://cashmeredreams.com/wp-content/plugins/super-forms/uploads/php/files/60d01abd6580e3b663f3b9985d3c6ad3/91158642928.pdf
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607deef4e0f4a---86869227651.pdf
    • http://dobryremont.pl/ebobas/portal/app/webroot/img/tmp/file/16207726109913.pdf
    • http://thaihotelsale.com/FileData/ckfinder/files/20210726_BE6E2AFCB5CF502F.pdf
    • https://laihouston.com/wp-content/plugins/super-forms/uploads/php/files/6b32076289acf1defacbf265e863c4a6/zorofaduzul.pdf
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/0fba819e84eca687918ca3f4db03da95/fovuru.pdf
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/d9b3880c95fb0c52ba9c93f36416e09d/tojadub.pdf
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/kik2ktphec9m0upt16vp8p75rg/40234760503.pdf
    • https://balaji-technology.com/userfiles/file/wawuxerizatinozibowed.pdf
    • https://www.bocamvigliesrooms.com/wp-content/plugins/super-forms/uploads/php/files/4150643e223a69e51402cb1a54f18b8d/66060204771.pdf
    • https://sfasg.jp/js/ckfinder/userfiles/files/gikopavotodefanawuturolaz.pdf
    • http://rothemtour.com/FileData/ckfinder/files/20210724_5360557087694CC1.pdf
    • https://betenagro.com/sites/default/files/file/bevomabisulovenixilagaxi.pdf
    • http://www.klpreschool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce1d71f5d4---88915967384.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_off0000dc07.bin
1330e7cc2c1f87ebb9542085f4575edf4d159c3765bc415505770d362e902834
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC07 10776 bytes
font_01_sfnt_off0000f4d6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF4D6 16792 bytes
font_02_sfnt_off00010ce8.bin
c0df34764d90fb9df622ecf8243bc0c7928afe9cb1d181a39e1bcc724665bbc9
pdf-font-stream PDF embedded font (sfnt) at offset 0x10CE8 16360 bytes