Malicious PDF — malware analysis report

Static analysis result for SHA-256 4578d593a5d144f1…

MALICIOUS

PDF

81.0 KB Created: 2021-09-10 11:00:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: 86b723c034f52ef41c3d54771d7f7c76 SHA-1: d29ec9a7614753547a43315b9a8bf73093fc354c SHA-256: 4578d593a5d144f17b46a979ed8541165922a46212a901449c8f10ecce5619a4
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses an urgency-based lure. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://synerhu.ru/uplcv?utm_term=u+dictionary+app+offline PDF link annotation
    • http://guitarenko.fr/img/files/44519617226.pdfIn PDF document text
    • http://ahkjt.com/upfile/file/60048390737.pdfIn PDF document text
    • http://cellesekorea.com/ckupload/files/65821267754.pdfIn PDF document text
    • https://optimuselearningschool.aels.edu/learning/site/images/uploadfiles/52919956795.pdfIn PDF document text
    • https://zenithoverseas.com/assets/userfiles/files/keduxukozulabik.pdfIn PDF document text
    • https://eghamatkade.com/basefile/eghamatkadecom/files/fonubopurotojazutub.pdfIn PDF document text
    • http://randygordonlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/letod.pdfIn PDF document text
    • https://bulendengin.com/upload/ckfinder/files/xekojokolilonomaxo.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/72562654419.pdfIn PDF document text
    • http://gma.ge/admin/ckeditor/ckfinder/userfiles/files/50980272353.pdfIn PDF document text
    • https://buddhaart.in/userfiles/file/zemodexudopa.pdfIn PDF document text
    • https://1snrpaulista.com.br/ckfinder/userfiles/files/88736200647.pdfIn PDF document text
    • https://cedria.es/DOCUMENTS/FotosFCKEditor/file/42653781391.pdfIn PDF document text
    • http://xn--54-dlcdkamdj4btild5b.xn--p1ai/ckfinder/userfiles/files/ketitugejod.pdfIn PDF document text
    • http://emblem4home.com/UserFiles/Member/File/31927415496.pdfIn PDF document text
    • https://graphicart.ro/fckfiles/file/diridanadedulimoxitoxi.pdfIn PDF document text
    • https://fedico.ca/upload/editor/file/zarunokerosarodarepebepat.pdfIn PDF document text
    • https://cengilli.com/icerik_images/file/fifafera.pdfIn PDF document text
    • http://agcslohian.com/userfiles/file/pikusabojuzi.pdfIn PDF document text
    • http://cw-cut.com/uploads/file/zejasajepulawugumef.pdfIn PDF document text
    • https://catwalkdogcome.com/editor_upload_image/file/57369957858.pdfIn PDF document text
    • http://webcertain.ca/contentupload/fckeditorUploads/organization_/file/vobifafodawidaza.pdfIn PDF document text
    • http://beiwendq.com/userfiles/file/22734599989.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/161378fc5ad3ff---81703228457.pdfIn PDF document text
    • http://canhtoanland.com/upload/files/4963353245.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_off0000d5ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5AB 10568 bytes
SHA-256: 596fa5691f58856a42789126128f84d37b296b08e63bc349c3a35db6cc7d69a2
font_01_sfnt_off0000ede7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDE7 18528 bytes
SHA-256: 4680b25548d2abdbea28011aadd1f553840a77437094dd7ddb3443e995c0834c
font_02_sfnt_off00011eb4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EB4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1