Malicious PDF — malware analysis report

Static analysis result for SHA-256 c83da39e7697a653…

MALICIOUS

PDF

84.5 KB Created: 2021-09-08 23:54:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 4f56685269162f5b34d4d1eaf3a08188 SHA-1: 40f4848d1df4050fe6c5a6502886303851bf9ec6 SHA-256: c83da39e7697a653d02ac9f0d0468bf4ea5b2cc68e378550f6e57b153d9b4c03
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a link farm pointing to compromised WordPress upload storage and disposable hosting, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The embedded JavaScript likely facilitates the execution of malicious actions or redirection to further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 7

  • 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.
  • 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 http://dellalontra.it/userfiles/files/98776288292.pdf In PDF document text
    • https://inprovitcaribe.com/ckfinder/userfiles/files/busiveweravivejazo.pdfIn PDF document text
    • http://robotsuk.com/luckingbros.co.uk/userfiles/files/3734230075.pdfIn PDF document text
    • http://gzcil.com/uploadfile/files/64782108034.pdfIn PDF document text
    • http://nocleginaplus.pl/uploads/userfiles/files/xavazawevelijaloxumajiw.pdfIn PDF document text
    • http://rzn-house.ru/upload/file/rinosusaxuwinuniru.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135bd7712921---33205727624.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/16137747863677---tazenuwu.pdfIn PDF document text
    • http://lexus-custom.com/js/upload/files/bologulemi.pdfIn PDF document text
    • http://wcsps.com.tw/ckfinder/userfiles/files/moxewunozanera.pdfIn PDF document text
    • http://kdwatch.net/upload/files/2021090423060145.pdfIn PDF document text
    • http://mathrainbow.com/userfiles/file/97916376634.pdfIn PDF document text
    • https://ketex.com/trcgp/ckfinder/userfiles/files/genofeliwukuxomat.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/1613771002beae---ganavosojenisulunozetar.pdfIn PDF document text
    • http://mrybalko.ru/files/wozedowegoberil.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/16138336a10c2b---9296999818.pdfIn PDF document text
    • https://imad0c0.com/js/ckfinder/userfiles/files/pusejozupes.pdfIn PDF document text
    • https://wsbtitan.com/images/file/73249535963.pdfIn PDF document text
    • http://gaytonfa.com/upload/files/tubowatefefi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=upgrade+android+samsung+s2PDF 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_off0000e57d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE57D 17792 bytes
SHA-256: 6cde1eab447233e7ea7f5dd7c5a2ed66be9d5a5090614f52f041e9a742e417b9
font_01_sfnt_off000113f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113F7 10820 bytes
SHA-256: 29cb4bba44297ac6f27dbd0546dc5f33c8a81426a33ba1f749d3cd9d0387b22f
font_02_sfnt_off00012cba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CBA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1