Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c931682d9189299…

MALICIOUS

PDF

75.4 KB Created: 2021-09-22 22:26:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 9fea3d08fb0086c7f059031d6d3514f4 SHA-1: 93591ccb31679e7815b3ce52b1c86c2a376db438 SHA-256: 8c931682d9189299d3e6d6f2f6bbfdab51c1ad06d2937a9c3f4e6c592beb2a33
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to various external URLs, some of which are hosted on compromised CMS platforms or disposable domains. The presence of embedded URLs and the nature of the link farm suggest an attempt to redirect users to phishing sites or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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=mortal+kombat+mobile+hack+ios PDF link annotation
    • http://nhatrangpalace.vn/app/webroot/upload/files/16783015246.pdfIn PDF document text
    • http://jezirka-biobazeny.cz/UserFiles/File/sezugajif.pdfIn PDF document text
    • http://rosesrealtyhomes.com/userfiles/files/gebewumevida.pdfIn PDF document text
    • https://www.iieng.org/editor/ckfinder/userfiles/files/68519755551.pdfIn PDF document text
    • http://cukiernia.eu/upload/files/letedav.pdfIn PDF document text
    • http://lisaarkinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/55629729314.pdfIn PDF document text
    • http://zae.me/datafiles/file/susefusofaf.pdfIn PDF document text
    • http://lnshiyue.com/userfiles/file/20210921173206_1411511581.pdfIn PDF document text
    • https://mallncart.com/userfiles/files/napatozotefet.pdfIn PDF document text
    • https://almudenafernandez.co/ckfinder/userfiles/Files/79168422283.pdfIn PDF document text
    • http://opakowania-loga.pl/zdjecia/fotki/file/taniwulema.pdfIn PDF document text
    • http://kulturazebrak.cz/userfiles/xipalenamop.pdfIn PDF document text
    • https://machnik.net/ckfinder/userfiles/files/87664706031.pdfIn PDF document text
    • http://exdebt.bg/userfiles/file/97564831436.pdfIn PDF document text
    • https://pergamine.com/ckfinder/userfiles/files/10051210903.pdfIn PDF document text
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/1614b056496b92---24889607705.pdfIn PDF document text
    • http://em-mould.com/ckfinder/userfiles/files/gojotuluniropiwa.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1613e167a4a4c1---12323568297.pdfIn PDF document text
    • http://moveworldtogether.com/datas/files/31027431656.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614162058da89---90975926677.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_off0000c22e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC22E 10616 bytes
SHA-256: ddc4e2b9989b8fa22f52bd5705dc93897ff661b28345710b62a5584c032b5665
font_01_sfnt_off0000da80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA80 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f292.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF292 17668 bytes
SHA-256: 487d6b9da306a00eed7ecd742db6bf9292a8a978ee8dbb88c67ad81a10210b91