Malicious PDF — malware analysis report

Static analysis result for SHA-256 7d77413bcdbb9b3e…

MALICIOUS

PDF

72.2 KB Created: 2021-09-27 19:10:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 25e1d86e59b5b87bcb266de5fbcdd09a SHA-1: db4b4740a2a5899d61b85994029ae8b9d0e0eff3 SHA-256: 7d77413bcdbb9b3e2fdb397cfc8aaf7635ed2c1773011238497fdfa17e7c6498
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to compromised websites, indicating a link farm designed to redirect users to potentially malicious content. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest this malicious intent. The ML classifier and ClamAV detection further confirm the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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
  • 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://cructi.ru/uplcv?utm_term=download+aplikasi+android+system+webview PDF link annotation
    • https://patoman.ro/ckfinder/userfiles/files/30881828203.pdfIn PDF document text
    • http://studiodugnani.it/userfiles/files/16072392572.pdfIn PDF document text
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/1899sish8g2080jh6j80n79ekb/gejez.pdfIn PDF document text
    • https://orangcar.com/app/webroot/upload/files/wisakuvusez.pdfIn PDF document text
    • https://neksav.com/upload/ckfinder/files/30547730879.pdfIn PDF document text
    • http://aitrans.cn/UploadFile/file/F1202109092047539927.pdfIn PDF document text
    • https://palet-school.com/files/files/romazevetofu.pdfIn PDF document text
    • http://www.colormotion.cz/UserFiles/file/sememanu.pdfIn PDF document text
    • http://architettosirocco.it/userfiles/files/sadusarezilidival.pdfIn PDF document text
    • https://tuoitre.bacgiang.gov.vn/lib/ckfinder/files/pafisitofolitut.pdfIn PDF document text
    • http://tourbusan.net/FileData/ckfinder/files/20210911_EC4D37009B76FCAE.pdfIn PDF document text
    • https://secolink.sk/userfiles/file/52248562923.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/1614bb5aeab77d---54695478433.pdfIn PDF document text
    • http://take114.kr/FileData/ckfinder/files/20210925_1D72FEB0298B1A54.pdfIn PDF document text
    • http://evo-models.com/uploads/userfiles/files/48536005779.pdfIn PDF document text
    • http://jinwoosmc.com/userfiles/file/43256194430.pdfIn PDF document text
    • https://inprovitargentina.com/ckfinder/userfiles/files/pajidiwaval.pdfIn PDF document text
    • https://asi-filter.pl/files/file/weremezovol.pdfIn PDF document text
    • https://pingthye.com/userfiles/files/75575803983.pdfIn PDF document text
    • http://bulgankhangai.mn/userfiles/files/mipatolufositezomufepoxi.pdfIn PDF document text
    • http://studiotecnicomartani.eu/userfiles/files/sosazinujugunot.pdfIn PDF document text
    • https://howardsteeves.com/wp-content/plugins/super-forms/uploads/php/files/a99eef8d35fd5db7d8764fabe145a939/rixajuriza.pdfIn PDF document text
    • https://hawkseyetravels.com/assets/ckfinder/userfiles/files/69331258095.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_off0000b19e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB19E 17972 bytes
SHA-256: 6c401b25bc70bfbcb3e2e5b927106ffb8c6f192ddf6b1d1276604f6289315897
font_01_sfnt_off0000dfcc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFCC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f7e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7E3 11052 bytes
SHA-256: c722329a6a937fdef1ea78c3f3653b60f0cd0526ff1cc76bd7a828e35bd57db7