Malicious PDF — malware analysis report

Static analysis result for SHA-256 1fcb88a783dd4eed…

MALICIOUS

PDF

77.5 KB Created: 2021-09-05 01:33:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 7169e98fe7451d8dfdbb2ea73208a1c4 SHA-1: ab3346cd904121fc955d15540f55f361200722ca SHA-256: 1fcb88a783dd4eedb53ba47bd00734c86e08a50a5fd35e9a6c1be35ea9d6492f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics as a link farm, with many URLs pointing to compromised or disposable hosting. The ML classifier and ClamAV also identified it as malicious, specifically as a phishing trojan. The document's structure and embedded links strongly suggest an attempt to redirect users to malicious content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • 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.
  • 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://latework.cz/soubory/32054827075.pdf In PDF document text
    • http://hbleg.com/admin/userfiles/files/puxowovubalujapafubaxo.pdfIn PDF document text
    • http://lionsmarsala.it/userfiles/files/futalipagejokega.pdfIn PDF document text
    • http://insidethedigitaltrend.biz/userfiles/file/gitavutuxolib.pdfIn PDF document text
    • https://areicon.com/images/file/95647093901.pdfIn PDF document text
    • https://ijacr.net/assets_admin/ckfinder/core/connector/php/uploads/files/tagukilukikusemokedelig.pdfIn PDF document text
    • http://4bx.pl/public/file/janojexariteduwofirep.pdfIn PDF document text
    • http://daedukgs.com/admin/fckeditor/data/file/20210710172345.pdfIn PDF document text
    • http://wagnerfamilyreunion.com/clients/866685/File/molud.pdfIn PDF document text
    • http://bmcnx.com/userfiles/file/loretan.pdfIn PDF document text
    • http://www.lightingandhvacexpo.com/wp-content/plugins/super-forms/uploads/php/files/28031684cd5cc6db438ae7e9b2e68c2f/zujajujexib.pdfIn PDF document text
    • http://www.sudaff.com/pics/file/39057121704.pdfIn PDF document text
    • http://glina-master.ru/admin/ckfinder/userfiles/files/kufefogi.pdfIn PDF document text
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/9kuc5n5ism4blb62thn7r6f9ld/pegaluzulatani.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086dbe284c1b---lokorupuxopukirepejajin.pdfIn PDF document text
    • https://www.tristar-technology.com/ckfinder/userfiles/files/74843143185.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/161149fbc59420---89845571172.pdfIn PDF document text
    • http://la-roofers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1611b0ad740955---zizupizefuzexaparebori.pdfIn PDF document text
    • http://qianshunqs.com/admin/upload/jujivepaxene.pdfIn PDF document text
    • http://pokewaveanaheim.com/uploads/files/69344181540.pdfIn PDF document text
    • http://pileshoppen.dk/userfiles/file/tefojeripuvunagub.pdfIn PDF document text
    • https://menokatea.in/ckfinder/userfiles/files/86730255295.pdfIn PDF document text
    • http://www.sindafaz.com.br/admin/editor/ckfinder/userfiles/files/rirukewezavemafu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=pivot+table+multiple+worksheets+2010PDF link annotation
    • 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_off0000cb85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB85 16740 bytes
SHA-256: 7c6f0c1fd5df3c1c7acca903aa0791c972252b9b3e560b8c4602abedea661cd2
font_01_sfnt_off0000f68d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF68D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010ea4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EA4 11192 bytes
SHA-256: 60a08eb3961dec76e39db1496613329dbbf067173b22b3145eb059975b01d62f