Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b1dfdb750b2998d…

MALICIOUS

PDF

75.1 KB Created: 2021-09-16 22:54:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b1d26602de0127c28872ba50bffc539a SHA-1: 41d48e94043f759251094eb2dee497ec6179f567 SHA-256: 4b1dfdb750b2998db136e73675b97152251cfaece7e7dd232067f167045f52c0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm pointing to multiple compromised websites, suggesting an attempt to trick users into downloading files. The presence of numerous links on disposable or compromised hosting reinforces the phishing and malicious download lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 http://cnokorea.com/userfiles/file/ruzit.pdf In PDF document text
    • https://galaxytraining.examinationonline.com/files/wapegifomunegomidogo.pdfIn PDF document text
    • http://zhengfutz.com/v15/Upload/file/202193114536036.pdfIn PDF document text
    • https://cobrawire.com/userfiles/files/7978064195.pdfIn PDF document text
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/7bd25c0150d8579ebc4c17fc5882acc5/75160651326.pdfIn PDF document text
    • http://purofirstli.com/userfiles/files/pusuveduriwedevaxoson.pdfIn PDF document text
    • https://inprovitbrasil.com/ckfinder/userfiles/files/pafujopazu.pdfIn PDF document text
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131da426b9ce---74023796618.pdfIn PDF document text
    • http://debten.net/UserFiles/File/89279023429.pdfIn PDF document text
    • https://coolinterier.sk/upload/files/36157061606.pdfIn PDF document text
    • http://csc020.com/userfiles/file/20210906121443_rs8g3r.pdfIn PDF document text
    • https://rgcsmt.org/ckfinder/userfiles/files/83041094684.pdfIn PDF document text
    • http://ydis.kr/userfiles/file/081436183496.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1613dae2d2d539---42521836905.pdfIn PDF document text
    • http://fourfoods.com/images/files/jalagazesetumaxemolekar.pdfIn PDF document text
    • http://rjt1.org/upload/files/nimuxiwanivemeg.pdfIn PDF document text
    • http://pcccmiennam.com/media/ftp/file/87324431299.pdfIn PDF document text
    • https://homecareangels.ca/files/files/files/lakuzirepolelesigesevowo.pdfIn PDF document text
    • http://cukiernia-waltar.pl/qcms/userfiles/file/51937050652.pdfIn PDF document text
    • http://silarperu.com/UserFiles/file/jixasulezejagulawog.pdfIn PDF document text
    • https://semineebrasov.ro/printuri-fi/files/79799135726.pdfIn PDF document text
    • http://cosmosimpex.com/app/webroot/ckfinder/userfiles/files/26553972701.pdfIn PDF document text
    • http://limobebe.com/userfiles/files/50336230820.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=cokernutx+download+androidPDF 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_off0000c1c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1C9 17220 bytes
SHA-256: bfb7db19295288b4fb8c9989f6592f183d709af9b8152fc480b4a3fa11316533
font_01_sfnt_off0000ee7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE7C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010693.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10693 10484 bytes
SHA-256: 592088d87a73203cc46f24f686d547d4d0370b5d813ec160d76bca2569db8e57