Malicious PDF — malware analysis report

Static analysis result for SHA-256 a492f28d9cb2c76d…

MALICIOUS

PDF

79.0 KB Created: 2021-09-19 13:11:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: ae593ef8c2e571517ac56eec22c999ba SHA-1: 809e6372d1cdb822d3ea5ee969a0d8f02d7d0057 SHA-256: a492f28d9cb2c76d42169a2adba36301b6f093d8c65c5884342f73f5c5b45bfd
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 a high ML score of 0.995817. It contains embedded JavaScript and a large number of external links, many of which point to disposable domains and appear to be part of a link farm, suggesting a phishing or malware distribution attempt. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating the document is designed to host numerous links on low-reputation domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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://crysiq.ru/uplcv?utm_term=vimage+free+apk+download PDF link annotation
    • https://kochitaxirental.com/ckfinder/userfiles/files/57296103569.pdfIn PDF document text
    • http://kerekesvillszer.hu/UserFiles/file/9838495786.pdfIn PDF document text
    • http://logisticsnetworks.net/ckfinder/userfiles/files/27517309106.pdfIn PDF document text
    • https://stepweystudy.com/ckfinder/userfiles/files/62745692141.pdfIn PDF document text
    • http://clinicaveterinariabilancino.it/userfiles/files/pudepagifalamo.pdfIn PDF document text
    • http://tcsm62.org/uploads/news/file/92044558230.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-9-16/20210916123805329419.pdfIn PDF document text
    • http://terwaarde.be/ckfinder/userfiles/files/pedatugokidike.pdfIn PDF document text
    • https://www.hmgfinance.com/ckfinder/userfiles/files/gasip.pdfIn PDF document text
    • https://quangcaowebsite.vn/uploads/files/88339546742.pdfIn PDF document text
    • http://jianianhuayule.a9188.com/upload_files/art_files/files/20210910_041243.pdfIn PDF document text
    • http://consulcongress.it/uploads/assets/file/muwibure.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613902636d9bb---48080574011.pdfIn PDF document text
    • http://doo-san.com/userfiles/file/20210905180319.pdfIn PDF document text
    • http://ohappy.org/userData/board/file/romapajajemo.pdfIn PDF document text
    • https://razdolle.by/wp-content/plugins/super-forms/uploads/php/files/l2phc2gtdcf9debe63del6jcs1/56064519143.pdfIn PDF document text
    • http://ig-einheitsloks.de/medien/file/5203345013.pdfIn PDF document text
    • https://transmilenio.net/datamont/userfiles/file/varulaw.pdfIn PDF document text
    • https://imihwa.com/uploads/image/20210918/files/20210918052933.pdfIn PDF document text
    • http://www.mananthavadynorbertines.org/www/js/ckfinder/userfiles/files/vunixuxemuwux.pdfIn PDF document text
    • http://www.medic-pneumolog.ro/fisiere/file/41657177701.pdfIn PDF document text
    • http://vatlieubaooncachnhiet.com/userfiles/file/70220921274.pdfIn PDF document text
    • http://teraval.cz/res/file/12443761711.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_off0000d05f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD05F 17868 bytes
SHA-256: 19c42224d28421c066043cc6a166cb69f672ab106e4305f94ae5f5b03a483545
font_01_sfnt_off0000fe5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE5A 10720 bytes
SHA-256: cec44ef96a8098f950fb3dc532ede986bca5cb2432567f31b02e7e0c05e85da2
font_02_sfnt_off000116b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116B7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1