Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c446ed8b00600c2…

MALICIOUS

PDF

79.8 KB Created: 2021-09-13 02:52:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 28d01cf0aec4a1a0f16ed3353d934e59 SHA-1: d0c502ce9e8db58677244056b4418add1268f941 SHA-256: 4c446ed8b00600c2c32ddd1eeb5f1f21a4a8bf77d328d47790dcd299841149e3
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and numerous external URIs, flagged by heuristics as a link farm and by ClamAV as a phishing trojan. The ML classifier also strongly indicated maliciousness. The embedded JavaScript likely facilitates the redirection to the listed external URLs, which are characteristic of phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://synerhu.ru/uplcv?utm_term=lol+android+release PDF link annotation
    • http://seghers.kr/data/editor/file/14479881786130111cdf337.pdfIn PDF document text
    • http://vssteel1999.com/ckeditor/userfiles/files/88949571293.pdfIn PDF document text
    • https://kratky.eu/files/file/mimirepoguzog.pdfIn PDF document text
    • http://jshtextile.com/UserFiles/file///lidatibuvig.pdfIn PDF document text
    • http://hanabi-la.com/uploads/files/52954906801.pdfIn PDF document text
    • http://darangyi.com/userData/board/file/88248330260.pdfIn PDF document text
    • http://brmxn.com/userfiles/file/20210903142608_xrmoie.pdfIn PDF document text
    • http://duonglaohanoi.com/userfiles/file/2990387515.pdfIn PDF document text
    • http://glassick.com/userfiles/file/xumop.pdfIn PDF document text
    • http://rintoyo.com/userfiles/file/tabubexerede.pdfIn PDF document text
    • http://www.performhabitat.fr/bundles/astadmin/js/ckfinder/userfiles/files/82726694432.pdfIn PDF document text
    • https://ww150006.linebot.net/upfile/files/20210906121012.pdfIn PDF document text
    • https://frontiermyanmar.com/sites/all/libraries/ckfinder/userfiles/files/99493172631.pdfIn PDF document text
    • http://sonnenheizung.ch/fckeditor/editor/images/file/sefatupusidasuxodapemu.pdfIn PDF document text
    • http://fitsiluet.cz/data/file/zirubusesikulus.pdfIn PDF document text
    • https://bonaparte.cappencms.com/templates/files/49397435534.pdfIn PDF document text
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/gnolu7ghg9ugvtordtq467g9tu/voxoluz.pdfIn PDF document text
    • http://autosvanbeek.nl/mindcms/js/ckf/userfiles/files/biliduwofekovoxepodulev.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/161313503f1f7a---92806322229.pdfIn PDF document text
    • http://egitara.com/upfiles/files/negekolusol.pdfIn PDF document text
    • https://firsatoyun.com/calisma2/files/uploads/lafolozenu.pdfIn PDF document text
    • http://centromedicoveterinarioadda.com/userfiles/files/mugesajewur.pdfIn PDF document text
    • https://keralahappyjourney.com/ckfinder/userfiles/files/62431991942.pdfIn PDF document text
    • https://abandassociates.com/ckfinder/userfiles/files/51269799665.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_off0000d3e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3E6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ebf8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBF8 18476 bytes
SHA-256: b367046054eb3d78937fbb1c1933ee3a6093ae38e867c8d55811e7a73613efb4
font_02_sfnt_off00011b60.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B60 10100 bytes
SHA-256: 5d879b065191036780398026f3029aa3c72dfd43f8ce10343062a0e3d112c711