Malicious PDF — malware analysis report

Static analysis result for SHA-256 3ef341d5ec44c955…

MALICIOUS

PDF

84.8 KB Created: 2021-06-14 13:54:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-23
MD5: 18d5d5859996306ab11b7d85d0a0d084 SHA-1: b0fe0c88323cfa496209733ca60688957888ed46 SHA-256: 3ef341d5ec44c9557de72356af1618e141b36c8118566046394bedc46925deac
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier. It functions as a link farm, directing users to various compromised WordPress upload directories and other domains, likely to distribute malware. The embedded URLs and the nature of the heuristics suggest an attempt to trick users into downloading malicious files disguised as software, such as 'nfs no limits mod money apk'. No scripts were extracted, but the PDF structure itself facilitates the redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://synerhu.ru/uplcv?utm_term=nfs+no+limits+mod+money+apk PDF link annotation
    • https://insights3.com/wp-content/plugins/super-forms/uploads/php/files/4a42ab505cfb2e870babcdac800cebfa/binasi.pdfIn PDF document text
    • https://medgarlci.com/wp-content/plugins/super-forms/uploads/php/files/d17a858f8a969d9b6c25c3ad007f6e17/42581443944.pdfIn PDF document text
    • https://ctsgroups.asia/images/file/69780993567.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093235d48db8---11412821401.pdfIn PDF document text
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608cd8c4dd4e0---86531058157.pdfIn PDF document text
    • https://gbagencement.fr/uploads/file/vogasovajud.pdfIn PDF document text
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/0a800188410ed4295d09a152fcaf1fcd/rorupupumevepoxovix.pdfIn PDF document text
    • https://alllegaltask.com/wp-content/plugins/super-forms/uploads/php/files/9h3ih5pi38o6i4vhqdk50mgktm/27933372920.pdfIn PDF document text
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607b7b4920a18---gapofurudif.pdfIn PDF document text
    • https://kopari.hu/files/file/netixibazurajozuf.pdfIn PDF document text
    • https://popa.com.br/wp-content/plugins/super-forms/uploads/php/files/5477d69b8ce57f0057c860f2bd501ebf/gefuluzexefojun.pdfIn PDF document text
    • https://www.beadvised.co.uk/wp-content/plugins/super-forms/uploads/php/files/18f0599a9436d733629de0eb1fac1615/74477922053.pdfIn PDF document text
    • https://medicinasolidale.org/wp-content/plugins/super-forms/uploads/php/files/f48eee44bbf6d11f08151d797514ca48/zofepi.pdfIn PDF document text
    • http://blueyee.com/upload/file/240209221081.pdfIn PDF document text
    • http://www.opentle.orgIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://www.gnu.org/licenses/gpl.htmlIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off0000f54d.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0xF54D 16568 bytes
SHA-256: 35eb98453d6449630e2a5b7ad87e701a19a86c099ee0c79520c6dafa89b0dc71
font_00_sfnt_off0000e389.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE389 5224 bytes
SHA-256: 5e1c84c91bb15f88d5e3b9468029f057d8a5159684537757cd66f51628724ec3
font_02_sfnt_off00012302.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12302 9840 bytes
SHA-256: 2699ff08bedc974e70cef9732e6c52e7fcf896cc50cd4847d600b9c3d17a4068