Malicious PDF — malware analysis report

Static analysis result for SHA-256 76aac5ad5821dfc3…

MALICIOUS

PDF

76.8 KB Created: 2021-09-18 08:43:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: fcc85a689169b4056d2718530851d07d SHA-1: 8ccd3ebc0f595f44aa7fa5d5b72fdb652f717a87 SHA-256: 76aac5ad5821dfc3c523051d8fa7261967dd0b4908210fa593f45531fbbbc8c1
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is often used to exploit vulnerabilities or redirect users to malicious sites. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of numerous external URIs, many pointing to PDF files on various domains, suggests a link farm or phishing campaign designed to distribute further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://mayersoffice.com/userfiles/file/musabalojakaz.pdf In PDF document text
    • http://vako.vn/app/webroot/uploads/files/wenukomexibafu.pdfIn PDF document text
    • http://car-zone.sk/data/data/file/sasutewolidomekojoso.pdfIn PDF document text
    • https://ahl2005.com/ckfinder/userfiles/files/panunizojew.pdfIn PDF document text
    • http://busto-wl.gattinonimondodivacanze.it/themes/userfiles/files/59232509529.pdfIn PDF document text
    • http://klaaswester.nl/img/file/91264472854.pdfIn PDF document text
    • http://dui-antidote.com/images/userfiles/file/64145598079.pdfIn PDF document text
    • https://fajanav.com/aym_image/files/juwedelubufojemepugapi.pdfIn PDF document text
    • http://bamila.vn/luutru/files/66135889610.pdfIn PDF document text
    • http://sanphamhanquocymy.com/uploads/files/sopako.pdfIn PDF document text
    • http://sieuthicayxanh.vn/webroot/img/files/59778422938.pdfIn PDF document text
    • http://kozszemle.hu/uploads/files/winejomufogugufulajoluwe.pdfIn PDF document text
    • http://www.hro.ait.ac.th/js/ckfinder/userfiles/files/jegez.pdfIn PDF document text
    • http://icmasistemas.com/userfiles/files/buliwuwetexabovan.pdfIn PDF document text
    • http://larben.cz/media/images/upload/file/1279955055.pdfIn PDF document text
    • http://sdv.sk/userfiles/articles/file/besaxefaxovanovovixar.pdfIn PDF document text
    • http://architettoannalisatinelli.it/userfiles/files/zavavuwavok.pdfIn PDF document text
    • https://rgcsmt.org/ckfinder/userfiles/files/87119846110.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/1612f1f811aeb8---28610204449.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613581119288b---zirilubutiraz.pdfIn PDF document text
    • http://shbaicun.com/userfiles/file/2021091813352473499.pdfIn PDF document text
    • https://vico-immobilien.com/ckfinder/userfiles/files/30203603453.pdfIn PDF document text
    • https://strategieb2b.com/userfiles/file/wujujoxovapi.pdfIn PDF document text
    • http://anabakorea.jp/userfiles/file/nepivetazorivudofijiwomij.pdfIn PDF document text
    • https://vietrocknet.org/app/webroot/img/files/bikexejikikaliganofefowin.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=excel+smooth+line+graphPDF 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_off0000c76b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC76B 10908 bytes
SHA-256: 1e4f3afbb4e6bdb23ac2436718bad624756da7646b1250f8cfc73d1987cad7cd
font_01_sfnt_off0000e07e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE07E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f890.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF890 17236 bytes
SHA-256: c694647abb065f7d2ce6da8f585a94c2ca7667da8cec8abb038d3d7a5bfa2074