Malicious PDF — malware analysis report

Static analysis result for SHA-256 fdf7553d6b08d8a9…

MALICIOUS

PDF

77.7 KB Created: 2021-09-22 12:32:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 4e8046c3a8070270d6b882489079c042 SHA-1: 942933370ed79f763ae97cff3cc0682fe4aea6f0 SHA-256: fdf7553d6b08d8a93c1ff40841c1fd55157eb93d7a22bf682ffe0c8a545816c2
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also contains numerous external URIs, including one pointing to 'inwebjor.ru', suggesting it's designed to redirect users to potentially malicious websites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://inwebjor.ru/uplcv?utm_term=pubg+mobile+with+obb+file PDF link annotation
    • http://mathrainbow.com/userfiles/file/8879414811.pdfIn PDF document text
    • http://chamdure.com/DATA/files/86972947420.pdfIn PDF document text
    • http://anonelectronics.com/admin/fckeditor/editor/filemanager/connectors/php/upload_jpg/file/202109191854147965.pdfIn PDF document text
    • https://suksesunited.com/contents/files/tusofudiwefokonimiraliz.pdfIn PDF document text
    • http://daydreamspin.com/userfiles/file/92317076897.pdfIn PDF document text
    • https://vjlabor.pitscovn.com/uploads/Upload/files/97159403527.pdfIn PDF document text
    • http://www.performhabitat.fr/bundles/astadmin/js/ckfinder/userfiles/files/niletitavomafewupes.pdfIn PDF document text
    • https://stephankeppel.com/userfiles/file/wegewenovetidufefuvegepew.pdfIn PDF document text
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614374408d73e---petenupotesutidesifet.pdfIn PDF document text
    • http://www.peritaonline.es/ckfinder/userfiles/files/divakezufixadujomuwu.pdfIn PDF document text
    • https://megalightgroup.lv/uploads/files/70573447200.pdfIn PDF document text
    • https://esprimagroup.com/userfiles/file/mokowija.pdfIn PDF document text
    • http://joltiy.ru/uploads/files/kudiwevavavejowadonivediw.pdfIn PDF document text
    • https://rallstarawards.us/nbloom/fckuploads/file/78287303098.pdfIn PDF document text
    • http://drukarnia-skawina.pl/app/webroot/media/files/xozimijininoxubor.pdfIn PDF document text
    • http://aokisuper.com/ckfinder/userfiles/files/pesapubevebaw.pdfIn PDF document text
    • http://omnoiptv.com/outscapes/admin/ckeditor/uploads/ck/files/fubexeraliwunegizopu.pdfIn PDF document text
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/3d50a8e454937f4aeb4f95584689d8a1/raputizokiti.pdfIn PDF document text
    • http://czechdidgeridoo.com/admin/upload/file/pefatuji.pdfIn PDF document text
    • http://saharun.org/uploads/ckfinder/userfiles/files/delojisesedubi.pdfIn PDF document text
    • https://aprenda-atdi.com/uploads/files/99835712230.pdfIn PDF document text
    • http://trans-serwis.com/userfiles/file/zazavupopoxuwidosit.pdfIn PDF document text
    • http://www.iuoelocal870.com/kaizen/ckfinder/userfiles/files/58280744217.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_off0000c01b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC01B 21636 bytes
SHA-256: 9aa5c631335b9c6f79cb4ead5a7d3d4de5c647bd866903dba2f77fab81de8a12
font_01_sfnt_off0000f9c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9C5 10452 bytes
SHA-256: 002956b1efa8c80c97fa9050743da99110e1b548e9547a7604caf6474a77d3ce
font_02_sfnt_off00011187.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11187 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1