Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8c4adeebc98c147…

MALICIOUS

PDF

78.8 KB Created: 2021-09-14 03:18:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 6ff9b3e41ae33f31578b537d9ea7a56a SHA-1: 73fb2c79c033a67116cdb2d286569a4de16df697 SHA-256: b8c4adeebc98c1479f6888b989f2f5f275a1cd62153ef8eeeaed57f099b09334
134 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as a phishing trojan and ML classifiers indicated a high probability of maliciousness. The document contains numerous embedded links, many pointing to PDF files hosted on potentially disposable domains, suggesting a link farm designed to obscure the ultimate malicious destination. The presence of a 'download button' heuristic further supports a phishing or social engineering attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://caudafotografia.com/userfiles/files/jolujerunoguxo.pdf In PDF document text
    • https://newsale.linyn.mobi/upload/ckeditor/pages/files/mobomuvobinikuv.pdfIn PDF document text
    • https://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/fb8f78406ff3350857d1563346d95f56/wumotolujejudo.pdfIn PDF document text
    • http://naitikfashions.com/ckfinder/userfiles/files/jenepalevaxaru.pdfIn PDF document text
    • https://zahrek.com/userfiles/file/tesaziketusirit.pdfIn PDF document text
    • http://kelvista.lt/images/files/23733429104.pdfIn PDF document text
    • https://wintechindia.in/ckfinder/userfiles/files/35548734722.pdfIn PDF document text
    • http://eca.or.th/ckfinder/userfiles/files/wimidejawoxaxezifogazes.pdfIn PDF document text
    • https://www.gpaci.org.br/cms/ckfinder/userfiles/files/bisef.pdfIn PDF document text
    • https://suruburi.net/mm/file/bixazofigivena.pdfIn PDF document text
    • http://paneldeconsos.com/userfiles/file/woduzakaxokenavumiwu.pdfIn PDF document text
    • http://berallebags.com/UploadFiles/FCKeditor/20210911033626.pdfIn PDF document text
    • https://noihoithanhtuan.com/media/ftp/file/wapugobemop.pdfIn PDF document text
    • http://www.ibadirect.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613474f55ca9a---fosajinifafomevomenu.pdfIn PDF document text
    • http://insfilings.com/skyzone_classic/upload/files/79849493687.pdfIn PDF document text
    • https://bunian-co.com/other_files/File/94665292641.pdfIn PDF document text
    • http://gima.ge/admin/ckeditor/ckfinder/userfiles/files/nunamep.pdfIn PDF document text
    • http://qwerty.pl/_data/file/josunuzopirogeraxizopalo.pdfIn PDF document text
    • https://geloracinta.com/contents/files/29673985407.pdfIn PDF document text
    • https://baoholaodong24.baohohoanglong.com/userfiles/file/789879180.pdfIn PDF document text
    • https://nepaltrekkinginhimalaya.com/assets/userfiles/files/64886075285.pdfIn PDF document text
    • https://bcbc3399.com/upload/files/mufefejuxavigimorepax.pdfIn PDF document text
    • http://www.mecateengenharia.com.br/ckfinder/userfiles/files/kalewomatefojojomukev.pdfIn PDF document text
    • https://pracowniatechart.pl/fckpliki/file/febujuturaguza.pdfIn PDF document text
    • http://avtokapriz42.ru/userfiles/file/jidotisi.pdfIn PDF document text
    • http://olguanaokulu.com/upload/file/90207716213.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=tubex+youtube+downloader+apkPDF 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_off0000c8c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8C6 10724 bytes
SHA-256: 34ae2a9ab33a7667d28464aa25c9818223d5b5e27ea2422bc0df7c452d13a523
font_01_sfnt_off0000e16a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE16A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f97c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF97C 20216 bytes
SHA-256: f7d45690baf0edfbbf3f41f36f5fc607de39d0bbad9d3af983be74b7d49059ea