Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f638da79c84b53d…

MALICIOUS

PDF

82.6 KB Created: 2021-09-09 04:12:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 5c2fc12a356148d3e0229168de404220 SHA-1: 50725c3f989be7b041daad5e09335e1a7caa2b63 SHA-256: 4f638da79c84b53d704beafc655a8e27a60af88e2be1ff3c8d2c9884734cc996
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ClamAV and an ML classifier as malicious. Heuristics indicate it functions as a link farm, directing users to multiple potentially compromised or disposable hosting sites. The presence of numerous unknown URLs suggests an attempt to distribute malware or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://sbriz.ru/userfiles/file/zexevenelagadelupizubume.pdf In PDF document text
    • https://nergizleryapi.com/image/files/vumutavujobegixoki.pdfIn PDF document text
    • https://wonwon.taipei/photo/file/67981619586.pdfIn PDF document text
    • http://ippon.lv/uploads/File/redarusuzejej.pdfIn PDF document text
    • http://gazetavk.ru/img/file/motixil.pdfIn PDF document text
    • http://3dtechgroup.com/uploads/image/files/51501110860.pdfIn PDF document text
    • http://yasairamenbar.com/uploads/files/gelija.pdfIn PDF document text
    • http://astprom.ru/sites/default/files/file/43045246859.pdfIn PDF document text
    • http://ukrkarta.ua/fckeditor/userfiles/file/73059591735.pdfIn PDF document text
    • http://saiprogetti.net/userfiles/files/mosanogopopagijatuwegat.pdfIn PDF document text
    • http://ng-sons.com/userfiles/file/62476402782.pdfIn PDF document text
    • http://arucax.am/user_images/file/wujegitowadide.pdfIn PDF document text
    • https://szallas-karpatalja.net/upload/81486440565.pdfIn PDF document text
    • https://thai-airpark.com/ckfinder/userfiles/files/31422959261.pdfIn PDF document text
    • http://gazdalkodjokosan.hu/img/userfiles/file/vagore.pdfIn PDF document text
    • http://mwflower.com/upimagesfile///xatelolobuwanuvumuja.pdfIn PDF document text
    • http://wlpp.net/images/blog/file/60645236025.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/ml5i3fkgatkouh63k4bcro2ub3/begiralefodepixireli.pdfIn PDF document text
    • https://elitteaccesorios.com/wp-content/plugins/super-forms/uploads/php/files/cbh3aqes2eur3kkbl2m9lh7m9f/22967268641.pdfIn PDF document text
    • http://cctsw.net/whly/up_files/FCK/file/20210908_110603_125.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/161314421cfdea---71548763247.pdfIn PDF document text
    • http://kamnitikamini.si/upload/files/98119277691.pdfIn PDF document text
    • http://indyskischool.com/ckfinder/userfiles/files/gumapigalalewuxe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=how+to+remove+update+on+androidPDF 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_off0000dbb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBB7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f3c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3C9 18884 bytes
SHA-256: 634f0f53f570b2c8b88b5abc42bd3e17c0c112eacfe5ae820d4793f6ccad845b
font_02_sfnt_off00012518.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12518 10584 bytes
SHA-256: 78c098f69d843f9a0b7bcba0a534eaf955ce5c82f8ecf9573227feb1d946fb47