Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4b43958863584a7…

MALICIOUS

PDF

80.9 KB Created: 2021-09-11 17:47:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: e26c60bf7a8a849ca3b154c6c05d7558 SHA-1: a2af67a373dc160071b85ca6e315f15aa03d73f2 SHA-256: d4b43958863584a7ed4f5e51d9af16c86ad6c8006df36f342f61be21ef139b40
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a PDF document identified as malicious by ML classifiers and ClamAV. It contains embedded JavaScript and a significant number of external URIs, many of which point to disposable hosting and are structured as a link farm. This suggests the document's primary purpose is to redirect users to external sites, likely for phishing or to download further malicious content. The ML classifier's high confidence score and the nature of the heuristics strongly indicate a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://bostaninsaat.com/image/files/60614162477.pdf In PDF document text
    • http://chunmianxian.com/upfolder/e/files/20210907115537.pdfIn PDF document text
    • https://glearningsolutions.com/userfiles/files/6410592929.pdfIn PDF document text
    • http://www.plain-pied.com/editeur/ckfinder/userfiles/files/dilora.pdfIn PDF document text
    • https://candica.pl/ckfinder/userfiles/files/wikobumexapabiz.pdfIn PDF document text
    • http://bajkolandia-leszno.pl/userfiles/file/54868333508.pdfIn PDF document text
    • https://www.fibertech1.com/my_content/js/ckfinder/userfiles/files/litakobemalizutowilofovug.pdfIn PDF document text
    • http://skyrunarser.com/js/fckeditor/editor/filemanager/connectors/php/connector.php/upfiles/file/2109012341516739767unlpc.pdfIn PDF document text
    • http://makinsushi.com/uploads/files/gidijitinaf.pdfIn PDF document text
    • http://mtegl.wsystem.sk/userfiles/files/ziwimufejizovo.pdfIn PDF document text
    • https://lekkermooi.nl/userfiles/file/wuxugatonitega.pdfIn PDF document text
    • https://cvsc.co/userfiles/file/9899631719.pdfIn PDF document text
    • http://garagehayashi.com/js/upload/files/61300116498.pdfIn PDF document text
    • http://joesservicecenternj.com/userfiles/files/ganom.pdfIn PDF document text
    • https://romalasergroup.com/userfiles/files/sixeliramexa.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613b864979862---37151482042.pdfIn PDF document text
    • http://nawaress.com/webroot/js/ckfinder/userfiles/files/7690787551.pdfIn PDF document text
    • http://hoaisonland.vn/upload/files/47984409205.pdfIn PDF document text
    • http://lotuscourtpune.com/wp-content/plugins/super-forms/uploads/php/files/308a8fad63c86e6d308176c04c7df1bc/32962670057.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=xmeye+apk+download+pcPDF 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_off0000d715.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD715 18380 bytes
SHA-256: 12ef4675cc93a2a41561d8154f40bdc59ae28651d51f0401683b50177fd8d3b2
font_01_sfnt_off000106d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106D5 10516 bytes
SHA-256: f8080a5bf8dfe384e63c999729bd586b9bad72f91f6859f5f83c57238e0e3605
font_02_sfnt_off00011ec5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EC5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1