Malicious PDF — malware analysis report

Static analysis result for SHA-256 6730975206f6ca9a…

MALICIOUS

PDF

79.0 KB Created: 2021-06-13 05:56:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: c4f51bc5a703aa72244b40e757abdd41 SHA-1: de918ddbf9db5ee1e9c5937ff7d4520e66dfb4f4 SHA-256: 6730975206f6ca9a6506cbb03125061b9efe48fb2bfeb8da39939e58b474c861
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm pointing to compromised CMS uploads and disposable hosting. The embedded URLs, such as 'https://ketchas.ru/uplcv?utm_term=toefl+official+guide+pdf', suggest a lure to download further malicious content, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://ketchas.ru/uplcv?utm_term=toefl+official+guide+pdf PDF link annotation
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c55516c0b66---2915254821.pdfIn PDF document text
    • http://www.segurosfacility.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a879bf98f93---89211633567.pdfIn PDF document text
    • http://strategie-online.net/catalogue_dynamique/file/wozojopurusukixururek.pdfIn PDF document text
    • https://intellicapital.in/ckfinder/userfiles/files/22887661581.pdfIn PDF document text
    • http://outspokenholland.com/userfiles/fckFile/20210529012531.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160792c6044408---fibabilanowife.pdfIn PDF document text
    • http://aexpress.lv/index/images/up/file/72973204395.pdfIn PDF document text
    • http://akinmedical.com/uploads/file/36222027197.pdfIn PDF document text
    • https://actioncoach.com.my/wp-content/plugins/formcraft/file-upload/server/content/files/160b46639afdb0---wulirifozo.pdfIn PDF document text
    • https://rebates.forex/wp-content/plugins/super-forms/uploads/php/files/ktiai1j1jgnnq5caniugm5s295/nomafalawifonoje.pdfIn PDF document text
    • http://selfmadefilms.nl/userfiles/files/delulituxigujegapi.pdfIn PDF document text
    • http://hrjok.com/uploadfile/file/piboviruwipiruxifijes.pdfIn PDF document text
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2612c83622---53736975418.pdfIn PDF document text
    • http://sewakendragroup.com/userfiles/file/74108397543.pdfIn PDF document text
    • http://4grd.com/cmsimages/file/79228822862.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e34e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE34E 4696 bytes
SHA-256: 1cff19dff17bb2467c8bf952283fe3e75ab3cd5fbd881d2172e2cf5add1b3d2f
font_01_sfnt_off0000f350.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF350 13912 bytes
SHA-256: 323c5be7494fa2b26775a8b337b589eebd6325eeba8f763ffd2afddaaf793822
font_02_sfnt_off00011faa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FAA 4324 bytes
SHA-256: 0d0f64e27578eb124b8bc81c7eceacdd166e22eddd95c81328e9fbd7de2a6333