Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4893d02b1353e03…

MALICIOUS

PDF

83.4 KB Created: 2021-09-18 01:55:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 54ea434c1940900a4d5731f5ea02ed08 SHA-1: 3afce3fbfa2e4267d7e786d671bba084614f3541 SHA-256: b4893d02b1353e039f12385353ef0e10a6119d01db2dd4f399225e61f0cf5467
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected by ClamAV as Pdf.Phishing.Trojan and an ML classifier flagged it with high confidence. The PDF contains numerous external links, many of which are hosted on disposable domains and appear to be part of a link farm designed to redirect users. One URL, 'https://coretry.ru/uplcv?utm_term=best+app+to+send+photos+from+iphone+to+android', suggests a phishing lure related to app recommendations. No scripts were extracted, but the PDF structure and numerous external links indicate a phishing or redirection attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 5

  • 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.
  • 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://coretry.ru/uplcv?utm_term=best+app+to+send+photos+from+iphone+to+android PDF link annotation
    • https://fa-vietnam.com/webroot/img/files/boxowurikokimosexabefede.pdfIn PDF document text
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bbc9ad86e6---48752852732.pdfIn PDF document text
    • http://gachmenminhchien.com/media/ftp/file/7575497324.pdfIn PDF document text
    • https://ddtoyz.com/ckfinder/userfiles/files/xonuti.pdfIn PDF document text
    • http://architettoseneca.com/userfiles/files/32779090972.pdfIn PDF document text
    • http://dhf-china.com/d/files/maborodub.pdfIn PDF document text
    • http://duquenne-moteurs.fr/webroot/upload/files/53474463543.pdfIn PDF document text
    • https://artcorner-fiberglass.com/userfiles/files/98265423988.pdfIn PDF document text
    • https://hogozaty.com/ckfinder/userfiles/files/batereb.pdfIn PDF document text
    • https://ferado.vn/userfiles/file/detisumiz.pdfIn PDF document text
    • http://jj-metals.com/userfiles/file/2021090421035173499.pdfIn PDF document text
    • https://ans5680.preneed91.com/upload/files/kajebokujalawexap.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161450e4328dc0---62836181997.pdfIn PDF document text
    • https://aihr-iadh.org/uploads/FCK_files/file/61788041348.pdfIn PDF document text
    • http://yanarfabrics.com/firma/files/getesafaxopitelajekisawa.pdfIn PDF document text
    • http://shengyaweb.com/uploadfile/file/2021090204344629.pdfIn PDF document text
    • http://devison-matras.ru/upload/file/608106773.pdfIn PDF document text
    • https://alperbehang.nl/userfiles/file/13504589357.pdfIn PDF document text
    • http://yugreat.com/filespath/files/20210905195805.pdfIn PDF document text
    • https://www.pharmawell.eu/ckfinder/userfiles/files/wifima.pdfIn PDF document text
    • https://raljob.com/userfiles/file/wixaxifax.pdfIn PDF document text
    • http://www.portaldasfreguesias.com/portugal/vianadocastelo/vianadocastelo/geraz_do_lima_sta_maria/ckeditor/ckfinder/file/53438556912.pdfIn PDF document text
    • http://makesrealsense.com/ckfinder/userfiles/files/wiwagope.pdfIn PDF document text
    • http://lerucherdesanges.fr/userfiles/file/katutijozefuvo.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_off0000e2ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2BA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fad1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAD1 10772 bytes
SHA-256: e5b1166fd943a4490f95d9779284f577b5e7067860161e1562a622d541be1cc3
font_02_sfnt_off00011369.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11369 17112 bytes
SHA-256: be2880ccc5cb429892c9c9f2f24b816c7ae2f93d1691a1592e4e6b6c447a8527