Malicious PDF — malware analysis report

Static analysis result for SHA-256 50e95cb86984557e…

MALICIOUS

PDF

77.6 KB Created: 2021-09-17 21:46:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 12a8d12ce855bf662f8becad11b893bd SHA-1: 887354ea0c17ed7183babed72639cfd01e5d6cb0 SHA-256: 50e95cb86984557e1bce0635492dd7248bf0393760058f737ec73a87d1bb4371
134 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript, which is often used to exploit PDF vulnerabilities or redirect users to malicious sites. The presence of numerous external URIs, many pointing to disposable hosting and using UTM parameters, suggests a link farm or phishing campaign designed to distribute further payloads or collect user information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • 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.
  • 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://allytemp.ru/uplcv?utm_term=quantum+theory+book+pdf PDF link annotation
    • http://mothertheresapublicschool.com/userfiles/file/bipitepuzuwadediwolej.pdfIn PDF document text
    • http://denda.co.kr/ckfinder/userfiles/files/gozowo.pdfIn PDF document text
    • http://niengrangchuyensau.com/upload/contentFile/file/50587396138.pdfIn PDF document text
    • http://chip-chup.hu/upload/file/juluvibobe.pdfIn PDF document text
    • http://tpokebar.com/uploads/files/sefisola.pdfIn PDF document text
    • http://kientrucsangtrong.com/plus/files/4455526551.pdfIn PDF document text
    • https://www.akilciilacdernegi.com/ckfinder/userfiles/files/20457402487.pdfIn PDF document text
    • http://ropesadventure.com/d/files/2014143611.pdfIn PDF document text
    • https://dukra.sk/editor_uploads/files/2972054270.pdfIn PDF document text
    • https://ta-taiwan.com/app/webroot/userfiles/files/fugotovajezizinag.pdfIn PDF document text
    • http://saveondealz.com/ckeditor/ckfinder/core/connector/php/uploads/files/77452359765.pdfIn PDF document text
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/16143db0d3b289---91368004260.pdfIn PDF document text
    • http://uts.edu.co/portal/app/ckfinder/userfiles/files/53326809549.pdfIn PDF document text
    • http://cloverdiamond.com/file/zilikomipevufokir.pdfIn PDF document text
    • http://elfobchod.cz/foto/Image/file/29458948518.pdfIn PDF document text
    • http://southerncross-ex.com/images/blog/file/15081397567.pdfIn PDF document text
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/f3f0e748628a6a2bab62b6d9a1d6ed87/rurijagako.pdfIn PDF document text
    • https://www.sherpachristain.org.np/ckfinder/userfiles/files/fidebudezemofiwevamifanod.pdfIn PDF document text
    • https://prosaison.fr/userfiles/files/piseriberajezotujudedob.pdfIn PDF document text
    • http://www.mananthavadynorbertines.org/www/js/ckfinder/userfiles/files/59811177172.pdfIn PDF document text
    • http://tweddlefoto.com/files_contenidos/upload/files/64604019754.pdfIn PDF document text
    • http://zeminyerkaplama.com/upload/ckfinder/files/tivubusab.pdfIn PDF document text
    • http://dom-2000.ru/ckfinder/userfiles/files/xexugurexu.pdfIn PDF document text
    • https://ncltandatbar.com/home/ncltandat/public_html/dowalumniusa/ckfinder/userfiles/files/53037517278.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_off0000c7a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7A3 18352 bytes
SHA-256: 0abf4dde347329e747663e05e9833646e9fe06f9209a248321278d46de226cdc
font_01_sfnt_off0000f7d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7D8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010fef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FEF 10964 bytes
SHA-256: 0a5dc926985dad4a2d7e9fad0914f64539c9f4ad34e18b806a70d45b2627a278