Malicious PDF — malware analysis report

Static analysis result for SHA-256 426d03ba86ad1408…

MALICIOUS

PDF

84.3 KB Created: 2021-09-11 21:52:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: abfc2647a60ebb63e498d3c06e570585 SHA-1: 83e098e6fad29ffc58203c126540af9ab51c3f84 SHA-256: 426d03ba86ad14088e97eda1465e042c2f4d1671345bf47c054254fd0d726eef
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous external URIs and is flagged as a link farm, with several links pointing to compromised WordPress upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and embedded URLs suggest it's designed to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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 https://medvor.ru/uplcv?utm_term=vsco+photo+and+video+editor+apk+download
    • https://efckrakow.pl/userfiles/file/tipifexitowaxonuxux.pdf
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/9095be4dfe5a203ffde3fef813d5df98/6074481466.pdf
    • http://rdasesores.gestconcursal.com/editor/ckfinder/userfiles/files/60204372587.pdf
    • http://zhodnoceni-penez.cz/is/images/FCKeditor/File/posopapelemi.pdf
    • http://anyimaker.com/upload/users/files/robirosako.pdf
    • http://olsztyntransportmedyczny.pl/userfiles/file/39991992251.pdf
    • http://bloomx.com/sites/all/sites/bloomx.com/files/jarizewaruvumun.pdf
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613491caa76c5---xeborozofifogiloxomewol.pdf
    • https://iva-vietnam.com/userfiles/file/7714476796.pdf
    • http://kibunajcc.com/ckfinder/userfiles/files/99940129901.pdf
    • http://studiotecnicofrisoli.com/userfiles/files/morusobigivegiluvakaban.pdf
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/16132405045ccb---fusivor.pdf
    • http://angelascanu.it/uploads/file/19481166570.pdf
    • http://proximeo.com/ckfinder/userfiles/files/69971466346.pdf
    • https://austarpharma.com/upload/files/bosemejupovegodejaza.pdf
    • http://minhledtran.com/luutru/files/23923630537.pdf
    • http://debrecen.varosom.hu/userfiles/files/41509199461.pdf
    • https://www.vigo.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16135db7d8e620---2190164493.pdf
    • http://forti.in/userfiles/file/33932346911.pdf
    • http://waxiangyuan.com/upload_fck/file/2021-9-9/20210909201910979386.pdf
    • http://nm-union.ru/ckfinder/userfiles/files/gevevamokemeruwetu.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e11a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE11A 16792 bytes
font_01_sfnt_off0000f92c.bin
28afa17a061d8c9b0da1b3d4109ab4a1d2de05e8232686f3d706e2a7dcdd81c6
pdf-font-stream PDF embedded font (sfnt) at offset 0xF92C 18972 bytes
font_02_sfnt_off00012b23.bin
705a2b1476b001247a8fe45e14e98865e4149740932a6a9102f9502fa77070cf
pdf-font-stream PDF embedded font (sfnt) at offset 0x12B23 10824 bytes