Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb849058552de8d7…

MALICIOUS

PDF

78.8 KB Created: 2021-09-10 20:45:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 0012427d62244dd9ef258464c130506c SHA-1: d730a9b3e4d9cf91acf66846275dd045aded0e73 SHA-256: fb849058552de8d75419e661f0b0abf6736c93d43c27c597a577adb1abc781cc
134 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and numerous external URIs, indicating it is designed to redirect users to malicious sites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests a link farm hosted on disposable domains, likely for phishing or malware distribution. The ML classifier and ClamAV detection further confirm its malicious nature, with the embedded JavaScript likely facilitating the redirection or payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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
  • 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://smidgel.ru/uplcv?utm_term=vertigo+self+treatment PDF link annotation
    • http://tw-echen.com/uploads/files/202109081137028521.pdfIn PDF document text
    • http://belniig.by/public/file/22407397028.pdfIn PDF document text
    • http://artgrafika.cz/userfiles/file/wuvulijabulolevuveg.pdfIn PDF document text
    • http://ammk.sk/userfiles/file/4761813089.pdfIn PDF document text
    • http://wordtmann.beckbauer.eu/ckfinder/userfiles/files/vunimisofebegirepeno.pdfIn PDF document text
    • http://sriagasthiyarastro.com/FCKeditor/userfiles/file/79451830335.pdfIn PDF document text
    • http://1day2night.com/UserFiles/file/23088372154.pdfIn PDF document text
    • http://hostingureitings.lv/uploads/userfiles/files/rutixarajukilavosufaj.pdfIn PDF document text
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/d6b9c041401912b5e0fe7f3008f7b63b/wobexura.pdfIn PDF document text
    • http://bumsnab.ru/uploads/files/76566145454.pdfIn PDF document text
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a2e984d1b0---gafogonuvu.pdfIn PDF document text
    • https://www.ventisilva.com.br/ckfinder/userfiles/files/xakemelibujizawasupinusu.pdfIn PDF document text
    • http://telegid.tv/userfiles/file/73674593742.pdfIn PDF document text
    • http://studiozammuner.eu/userfiles/files/wamotabekujesututisusu.pdfIn PDF document text
    • http://shtaket46.ru/page_edit/_samples/userfiles/files/vowibubezezejifimufob.pdfIn PDF document text
    • http://thegrcinstitute.org/app/webroot/js/ckfinder/userfiles/files/zunoxu.pdfIn PDF document text
    • http://kantipursecurity.com/userfiles/file/pulukadexuxaxumamofiferoz.pdfIn PDF document text
    • https://nibrasimansch.com/userfiles/files/xamafuj.pdfIn PDF document text
    • http://www.sanjuktabanerjee.com/fckimages/file/36103647495.pdfIn PDF document text
    • https://shastriratanchatterjee.com/ckfinder/userfiles/files/71015271381.pdfIn PDF document text
    • http://gpe-el.pro/ckfinder/userfiles/files/penogesadugek.pdfIn PDF document text
    • https://mimpiindahsatu.com/contents/files/binivebijewojuremikavibi.pdfIn PDF document text
    • http://caythuocnam.org/images/files/rupenijutemiratomu.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_off0000d49e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD49E 16264 bytes
SHA-256: e6d94435507837221b12adb029fc6a59ddf894bed559bb04d16fcf845bc52433
font_01_sfnt_off0000fe52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE52 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011669.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11669 10524 bytes
SHA-256: 1576d462224f18a678de7e47bd18c0e1d44772ff5c6b40f086d3ad649b39e6f8