Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3668b3cdbd8a82b…

MALICIOUS

PDF

83.7 KB Created: 2021-09-21 03:07:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 6208437779a086e72d3249e1ad6f3803 SHA-1: 2c6d70b9c01acc5834137449059552f1182be380 SHA-256: a3668b3cdbd8a82bd71b301809227265f9fab4be27f0312dd752e0cbb2d1836d
154 Risk Score

Malware Insights

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

The sample is a PDF that impersonates a cloud document lure, aiming to trick users into downloading further malicious content. Heuristics indicate it's a link farm designed to host multiple malicious PDFs, and ClamAV detection confirms its malicious nature. The presence of numerous unknown URLs suggests a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Cloud document impersonation lure medium SE_CLOUD_DOC_LURE
    Document impersonates a cloud file-sharing service such as SharePoint, OneDrive, Google Drive, Dropbox, Box, or Microsoft 365 and asks the user to open, verify, or access a shared document
  • 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://hk-sai.com/ckfinder/userfiles/files/37758555765.pdf In PDF document text
    • https://www.edm-medical.net/ckfinder/userfiles/files/48781448304.pdfIn PDF document text
    • http://infoegrafica.com/userfiles/files/kodene.pdfIn PDF document text
    • http://solamsys.com/userData/board/file/tunoxep.pdfIn PDF document text
    • http://kanizsakran.hu/userfiles/file/16978916523.pdfIn PDF document text
    • http://melodylavernebettencourt.com/media/file/xenevelufafur.pdfIn PDF document text
    • http://businessnavigator.in/ckeditor/uploads/files/50686277313.pdfIn PDF document text
    • http://ryanoomen.nl/uploadimages/files/wosovotusesixad.pdfIn PDF document text
    • http://elsped.hu/files/file/63756996962.pdfIn PDF document text
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/67dqoc69bircua8ns4cnpe8cda/fofon.pdfIn PDF document text
    • http://jayeonrak.com/upfile_editor/2021/files/23828882309.pdfIn PDF document text
    • https://cubic.is/userfiles/file/zizepixogekodobogug.pdfIn PDF document text
    • https://stpeterscbs.ca/ckfinder/userfiles/files/29227160995.pdfIn PDF document text
    • https://digireg.cz/upload/99929761146.pdfIn PDF document text
    • http://mtkshop.com/images/uploads/file/xeguxubak.pdfIn PDF document text
    • http://daegyung.kr/userfiles/file/20210905040313.pdfIn PDF document text
    • http://terhautz.com/upload_files/files/nemepugo.pdfIn PDF document text
    • http://knx-shop.ru/admin/ckfinder/userfiles/files/tefovovamegive.pdfIn PDF document text
    • https://rpaxis.net/userfiles/file/19273437353.pdfIn PDF document text
    • https://kattliv.com/kattliv/admin/userfiles/file/5035915522.pdfIn PDF document text
    • http://metalzilembo.it/userfiles/files/xenoden.pdfIn PDF document text
    • http://cbgnfinance.com/userfiles/file/68994206222.pdfIn PDF document text
    • http://wisdomtours.net/upload/file/tevazovedifamosevukav.pdfIn PDF document text
    • https://procogs.com/FCKeditor/file/4870589342.pdfIn PDF document text
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/161386ce0808e5---88262356320.pdfIn PDF document text
    • https://angkagenap.com/contents/files/wafowap.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=tera+box+cloud+storage+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_off0000e304.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE304 10892 bytes
SHA-256: b3017f12091c55f93f4fa8b6804de5815134698fa46dd1bd3ed30ed6d8b8f22e
font_01_sfnt_off0000fbfd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBFD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001140f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1140F 17420 bytes
SHA-256: d49958c3762e9940df544fa77487b55615f2c3128860081b035b083f7eddf029