Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d7a7cfba233211a…

MALICIOUS

PDF

81.8 KB Created: 2021-09-19 12:18:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: e4b25ee16a68c9e1fb03dee55f88cf13 SHA-1: 8f9b69a1aae9b08751e3e4f6c8d0f56d6520c5a9 SHA-256: 4d7a7cfba233211afcae0da5183cbd1e9f7274a3f055352702d836bc36777a87
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which are part of a link farm hosted on disposable domains, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of malicious redirection, likely leveraging techniques such as spearphishing attachments to deliver users to these sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://queure.ru/uplcv?utm_term=ola+party+apk+mod PDF link annotation
    • http://www.sushmitamukherjee.com/fckimages/file/9458885993.pdfIn PDF document text
    • http://sdes.in/uploads/wibutusagol.pdfIn PDF document text
    • http://lawyergz.net/uploadfile/files/79694006302.pdfIn PDF document text
    • http://www.mousumibanerjee.com/fckimages/file/97101390114.pdfIn PDF document text
    • http://dreambeauty.kr/upload/fckeditor/file/zedut.pdfIn PDF document text
    • http://cheers-gifts.com/userfiles/74503504419.pdfIn PDF document text
    • http://hoya889.com/upfile/files/20210909085606.pdfIn PDF document text
    • http://okzawidow.pl/img/upload/files/bavejorigijizaw.pdfIn PDF document text
    • https://insights3.com/wp-content/plugins/super-forms/uploads/php/files/f501b400219205f6f184bba39cf4ab6f/xeragufexofotadadosa.pdfIn PDF document text
    • https://airin.lv/images/userfiles/file/jobodipuvogoxuraxe.pdfIn PDF document text
    • http://j-club.eu/userfiles/file/buwuwugukaratazesupuzu.pdfIn PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/16140f5b4c339b---nosixawepulotawitosini.pdfIn PDF document text
    • https://harshahometutors.com/uniformkontakt/userfiles/image/files/60912454395.pdfIn PDF document text
    • http://progetec.org/userfiles/files/linufodisowiforukazirim.pdfIn PDF document text
    • https://espritgt.com/userfiles/file/69649429486.pdfIn PDF document text
    • http://njuhome.pl/ckfinder/userfiles/files/tiduwurijopetibusi.pdfIn PDF document text
    • https://phuketwebstudio.com/ckfinder/userfiles/files/7734060916.pdfIn PDF document text
    • http://linuxnewyork.com/draft/media/62573887343.pdfIn PDF document text
    • https://people11people.com/uploads/File/gebofuvijevizixumeb.pdfIn PDF document text
    • http://immobilieninvestors.eu/userfiles/file/40224319691.pdfIn PDF document text
    • http://michelschuurmans.nl/images/uploads/file/4764696647.pdfIn 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://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_off0000dd25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD25 17592 bytes
SHA-256: 3a8811ece508476ad1a3f5f61506d887e681c9126169e5c40b2b1b5e62825336
font_01_sfnt_off00010b03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B03 10288 bytes
SHA-256: fd88c426317f3bef8039931c6daa7fb2cb7d1a8dfb70837bbbd34b1a16bba1b2
font_02_sfnt_off00012243.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12243 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1