Malicious PDF — malware analysis report

Static analysis result for SHA-256 273cd742bb5fac48…

MALICIOUS

PDF

75.1 KB Created: 2021-06-14 14:53:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: 65dfed7e52eaba911fc362db6aa0ec10 SHA-1: 18332ebca168e71af3968f56f172a518d90f130e SHA-256: 273cd742bb5fac4875899005483d96c756d3ea10dbe6163178f23d4fdfea343c
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 a machine learning classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress upload directories and other disposable hosting. These links likely lead to phishing pages or further malware downloads, aligning with the characteristics of a malicious document used for initial access via spearphishing.

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://infrive.ru/uplcv?utm_term=adverb+plus+adjective+examples PDF link annotation
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/1606cbc9ca922d---21139914767.pdfIn PDF document text
    • http://drstevealbrecht.com/wp-content/plugins/super-forms/uploads/php/files/542b766bf02237308245fc8f47aff4bf/46668321692.pdfIn PDF document text
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/a447b00707732dcc81ee04c88238ed09/logokisikijomofepubozaxup.pdfIn PDF document text
    • http://hit-air.pro/ckfinder/userfiles/files/29813624030.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/b1fc39646fe18bb12507fcf6e845179d/9768161318.pdfIn PDF document text
    • http://www.gonouvellezelande.com/files/sijafajotikosemavimibozap.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/vemuf.pdfIn PDF document text
    • http://thaiboxes.com/piceditor/file/jufasogu.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a3bd022a02---fupadosojubofoxigawov.pdfIn PDF document text
    • http://crmrealty360degree.in/userfiles/file/kanulopiredalomaxukibubi.pdfIn PDF document text
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/1607b1148e0012---48270517465.pdfIn PDF document text
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/e4fadb27f33004d6bf178b88181243d6/35049269256.pdfIn PDF document text
    • http://www.pianoszimmermann.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607cab8cb38b8---vebememiwaragopo.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/22b0a308fd1289a4ade7a867f5352c11/lufexeziz.pdfIn PDF document text
    • http://artospace.com/pics/file/jewegotoz.pdfIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e6a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6A2 5552 bytes
SHA-256: d63847731c53936131a12869356d63c052400b6cf77d0d87a2d46d69ad5a1c52
font_01_sfnt_off0000f979.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF979 10752 bytes
SHA-256: 62a2bfe34e1813cee9d0af9b142f0f5fc7a386a8ea6cb710687a53064a8b3f70