Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a9e81f6c1af2d94…

MALICIOUS

PDF

72.6 KB Created: 2021-09-25 17:56:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 11288849bf20755653849eaaddad49e5 SHA-1: 77314c3885d677462a853471533a32da0e3df850 SHA-256: 8a9e81f6c1af2d94ec0ca3f8b3eb8d5edea6e31d6f575e42643c8e7dea33f5f2
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are part of a link farm hosted on disposable or compromised domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery through these links. The presence of embedded JavaScript suggests potential for further exploitation or obfuscation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9915

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
  • 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://cructi.ru/uplcv?utm_term=tv+channels+app+for+android+tv
    • https://empezo.xyz/js/ckfinder/userfiles/files/loweretopese.pdf
    • https://sssmri.com/ckfinder/userfiles/files/nigudobinulinaxora.pdf
    • https://wisestudentz.com/userfiles/file/fezukudajamunazupatuga.pdf
    • http://ndc-group.ru/uploads/files/biboduvobopigizotabigaxog.pdf
    • http://tyros-club.de/userfiles/file/13669337829.pdf
    • https://www.ogblfrontaliers.fr/wp-content/plugins/super-forms/uploads/php/files/8d8q9ivbu52cn7temudckmgkcb/82828071918.pdf
    • https://manajrgvaaradhi.com/cms-uploads/files/71516241494.pdf
    • https://swapnauraan.com/ckfinder/userfiles/files/33269130127.pdf
    • http://f-okinawa.com/img/tmp/files/kexavegesakawo.pdf
    • http://royalwedding.jp/images/blog/file/vobupokozim.pdf
    • https://balticstroy.com/uploads/files/ludiwinivabubetabaziji.pdf
    • https://ateneoarbonaida.com/wp-content/plugins/formcraft/file-upload/server/content/files/161454975a05a6---22866702158.pdf
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614c07702aef0---papomuvadimuranepibabo.pdf
    • http://oppedisanorobertosrl.com/userfiles/files/17568592948.pdf
    • http://lapmaymn.samdigroup.vn/app/webroot/upload/files/73473056420.pdf
    • https://vieclamday.com/userfiles/file/relenikevujubilewamuja.pdf
    • http://emailreceptionist.net/userfiles/file/jotupitodigep.pdf
    • https://mongolia-volkslift.com/uploads/files/jozosimor.pdf
    • http://sanchariglobal.com/userfiles/file/gepikodevodozolezeke.pdf
    • http://electric-kernbichler.at/pisemodalofukexe.pdf
    • http://automsystem.com/UploadFile/file/20210913062454287.pdf
    • https://thebillionbottom.com/business_school/uploads/file/24032286132.pdf
    • http://hexindechem.com/upload/files/84077587924.pdf
    • http://ks4073.com/file_media/file_image/file/16828897968.pdf
    • http://laxycoffee.com/upload/files/8204898379.pdf
    • http://skyrunarser.com/js/fckeditor/editor/filemanager/connectors/php/connector.php/upfiles/file/210906153827442337ygeg4x.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_off0000b77e.bin
b62722bf9db3ab747ad5d32b613396d0c6c9c2eebb27b9adc6924d85db90c7e9
pdf-font-stream PDF embedded font (sfnt) at offset 0xB77E 10748 bytes
font_01_sfnt_off0000d025.bin
687851cc81da1515f05bb5fec249474c4359d5e6a63823731b7f8da9df90c755
pdf-font-stream PDF embedded font (sfnt) at offset 0xD025 17476 bytes
font_02_sfnt_off0000fc74.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFC74 16792 bytes