Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b8d7baa3f57a997…

MALICIOUS

PDF

84.8 KB Created: 2021-09-18 03:53:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 6fbf5c758c85c21cca9a761d0c44c927 SHA-1: be46fc4125adb7bc9e686635731fb6b1dd06d2fb SHA-256: 2b8d7baa3f57a9976bb81a67c6a15c246bfe60a931ec21914dfe49216de266a3
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and a large number of external URIs. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests the document is designed as a link farm on disposable hosting, pointing towards a phishing or malware distribution scheme. The embedded JavaScript likely facilitates the redirection to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://medvor.ru/uplcv?utm_term=the+fast+and+the+furious+full+movie+123movies PDF link annotation
    • http://vstarmp.cn/upload/files/20210903_141238.pdfIn PDF document text
    • http://www.enfersalus.com/ckfinder/userfiles/files/miwaboxotojever.pdfIn PDF document text
    • http://tanabuauto.com/js/upload/files/75674555822.pdfIn PDF document text
    • http://hbaoge.com/upload/files/kutixufomulakajem.pdfIn PDF document text
    • https://www.hinkler.com.au/application/third_party/ckfinder/userfiles/files/93467840367.pdfIn PDF document text
    • http://defhjdrjioo.friend-match.com/upload/files/jejowukewenajaledixubib.pdfIn PDF document text
    • http://happinessgown.com/upload/users/files/39961059125.pdfIn PDF document text
    • http://posekatzahradu.cz/files/file/torim.pdfIn PDF document text
    • http://izhar-energy.com/userfiles/file/21449385103.pdfIn PDF document text
    • http://proclima-membranes.ru/userfiles/file/ferevebasevironom.pdfIn PDF document text
    • https://wsbtitan.com/images/file/luwox.pdfIn PDF document text
    • http://agro-partner.com/Image/files/nevisagi.pdfIn PDF document text
    • http://stagelight.pl/userfiles/files/setumekerof.pdfIn PDF document text
    • http://geometracosentino.com/userfiles/files/65019243033.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141e51e960a7---zejevirawipufemuzukedetag.pdfIn PDF document text
    • http://sunwisechem.com/Uploadfiles/files/56603919452.pdfIn PDF document text
    • http://skybuildinfraprojects.com/uploads/futukexowuz.pdfIn PDF document text
    • http://www.biharikft.hu/bihari-admin/ckfinder/userfiles/files/sasugaluxonigaremuzow.pdfIn PDF document text
    • https://quangcaowebsitecomvn.xemlaco.com/uploads/files/20693579039.pdfIn PDF document text
    • http://cukrarska-vyroba.cz/UserFiles/File/30384859422.pdfIn PDF document text
    • http://ericshartman.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/mofiko.pdfIn PDF document text
    • http://kronospan-mofa.hu/editor_up/7489148166.pdfIn PDF document text
    • https://szemvidito.hu/sfwkr/feltoltesek/Images/Image/wulimulironataw.pdfIn PDF document text
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/243b48f9d71aeaa2086b5546c81c3205/72814035230.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_off0000e486.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE486 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fc9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC9D 11092 bytes
SHA-256: 2cfe94a864c26b81b7107f50b98231be5cbcd499d578987a0903201dbb90254a
font_02_sfnt_off0001166a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1166A 18252 bytes
SHA-256: 0344b6adb0ec1bb62bb117f57946ef2a81e206a50ce9a8cf48175e78cb64a922