Malicious PDF — malware analysis report

Static analysis result for SHA-256 66c22e4be80ab7d7…

MALICIOUS

PDF

89.3 KB Created: 2021-09-11 12:00:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6f572d5da684cdcfedbc366a77ca8553 SHA-1: 4486ebb1275d80f76d5fb001aae5b9c703f14d01 SHA-256: 66c22e4be80ab7d77fb64398c217269300630fc35567caeee8763d194c962589
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and a large number of external URIs, many of which point to compromised CMS upload directories. These links likely serve as a link farm to redirect users to malicious content, as indicated by the 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9934

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 http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1613c294a00302---remixulotu.pdf
    • https://epgeptech.hu/ckfinder/userfiles/files/jodomonifadijaruwovoli.pdf
    • http://celyroknaterase.sk/editor_uploads/system/files/zukagotetevomidigelalot.pdf
    • https://www.gpaci.org.br/cms/ckfinder/userfiles/files/81780002425.pdf
    • http://msci.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/161375a1ae40cd---vogofiporifiduj.pdf
    • https://spcinternational.in/ckfinder/userfiles/files/gejikojurewetiniti.pdf
    • http://dglytbt.com/upfolder/e/files/20210907213209.pdf
    • http://thuaphatlailongthanh.vn/upload/contentFile/minhchau/file/24932862267.pdf
    • http://chickendaylacrescenta.com/uploads/files/2364816007.pdf
    • http://kondicionery-shodnya.ru/upload_picture/file/wopogo.pdf
    • https://repairbase.net/FCKeditor/editor/filemanager/connectors/php/images/file/wugupiv.pdf
    • https://giltmorestukko.hu/ckfinder/userfiles/files/rorufowomeloganug.pdf
    • http://acpiindia.com/userfiles/file/55371568784.pdf
    • http://sugarfree-gelato.com/upload/file/dibuba.pdf
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/uddm8j5mre4u4ds95k3jdim4v5/tarunapezamodijigarekeka.pdf
    • http://blueyee.com/upload/file/061819476231.pdf
    • http://hyundaidongdo3s.com/images/files/23905980630.pdf
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130c922c0183---88294396195.pdf
    • http://paintmaster.hu/js/ckfinder/userfiles/files/buboxevukibuvifakuburosut.pdf
    • https://thietbixanh.net/uploads/files/91450089742.pdf
    • http://www.kymkarajok.net/tiedostot/files/negimodugufakitebasoniz.pdf
    • http://pensjonatagat.pl/userfiles/file/fuzuzaf.pdf
    • http://petrduchek.com/files/raxidifagiwokowavikosewe.pdf
    • https://jokerprod.net/userfiles/file/57415955659.pdf
    • http://allier-genealogie.org/File:/30986672751.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=noon+academy+app+apk
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d641.bin
1c024217ce21bb66922f73502146d3c7616b47413e2e194c36dd680b30e64e78
pdf-font-stream PDF embedded font (sfnt) at offset 0xD641 16148 bytes
font_01_sfnt_off0000ebcd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEBCD 16792 bytes
font_02_sfnt_off000103e4.bin
7bff1331461cb74fce3c498e556bf50315aec1e49437ba062d955274c2089cd3
pdf-font-stream PDF embedded font (sfnt) at offset 0x103E4 10352 bytes
font_03_sfnt_off00011b46.bin
0b51ebff29ad85eb7e61adf611c35744994faaba0f91eeac4d840c603e6dcc7b
pdf-font-stream PDF embedded font (sfnt) at offset 0x11B46 22740 bytes