Malicious PDF — malware analysis report

Static analysis result for SHA-256 a636adc22dbbe0cf…

MALICIOUS

PDF

80.6 KB Created: 2021-09-11 04:54:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 8c1d1bd8972b13f5461532b57e52e08d SHA-1: fdb86ae63658563b23fc5193df3af6b1713013c1 SHA-256: a636adc22dbbe0cfded2a0aee43f066c1a823513e5b5b70eb567109b96069bed
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external PDF files hosted on various domains. The presence of numerous unknown URLs suggests a campaign to distribute further malicious content or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

Heuristics 5

  • 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.
  • 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 http://heatexchangersolution.com/upload_fck/file/2021-9-4/20210904052812113597.pdf In PDF document text
    • https://senesi-sklad.cz/userfiles/file/36823314095.pdfIn PDF document text
    • https://mtestbd.com/assets/uploads/files/kevifowa.pdfIn PDF document text
    • https://movimientofamiliadejesus.com/images/uploaded/file/tikonosozowoli.pdfIn PDF document text
    • http://mnarch.it/userfiles/files/9538063554.pdfIn PDF document text
    • http://emiem.pl/public/upload/ckfinder/userfiles/files/67412459790.pdfIn PDF document text
    • http://gitishahjahanpur.org/ckfinder/userfiles/files/dinuzoxamunar.pdfIn PDF document text
    • https://lexconsulting.ro/webroot/files/media/bufedibopolosepejon.pdfIn PDF document text
    • http://nsmpublicschool.org/slbdavbatala/userfiles/file/79227376607.pdfIn PDF document text
    • http://webmba.fr/client/logo/file/48769276084.pdfIn PDF document text
    • https://2ruoteexpo.it/ckfinder/userfiles/files/53616804856.pdfIn PDF document text
    • http://gps-ambroisie.com/ressource/site-image/files/fafasevavinepegivetupobi.pdfIn PDF document text
    • http://ctnphrae.com/ckfinder/userfiles/files/zawit.pdfIn PDF document text
    • http://myappartement.de/web/editor/files/18373643483.pdfIn PDF document text
    • http://pagyesa.org/userfiles/file/20210910043510.pdfIn PDF document text
    • https://reparationmobile.net/userfiles/file/87267322110.pdfIn PDF document text
    • https://nbretail.com.vn/ckfinder/userfiles/files/18950565648.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613bbf59b687a---2605386574.pdfIn PDF document text
    • https://mahanakhon.pacedev.com/ckupload/files/nevolagipune.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/3fa7871362ba14405366d3d30ee87328/xuwagogeni.pdfIn PDF document text
    • https://cylinder96.ru/admin/ckfinder/userfiles/files/67944402600.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=strike+force+kitty+onlinePDF 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_off0000d420.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD420 18996 bytes
SHA-256: f681a2b3f76e3cc03a5cfdebd7ece47609a819157f9491e9290baf412a7a1654
font_01_sfnt_off000105da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105DA 10280 bytes
SHA-256: 6858fb10832499650a964f61e6f6519c1d3bfad85325aa1b1f46a9e06167fc5c
font_02_sfnt_off00011d21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D21 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1