Malicious PDF — malware analysis report

Static analysis result for SHA-256 e20da836df5780f2…

MALICIOUS

PDF

83.9 KB Created: 2021-09-20 18:52:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: b70ac4a1544ec97dbe48fea365a916f8 SHA-1: 3090a53b0a279c7c4b61764d69666f0ff74b8d45 SHA-256: e20da836df5780f2548828eae97d4ad8471f7ee50de759063d9aae577a38c288
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm on disposable hosting. The embedded URLs and the PDF structure suggest an attempt to redirect users to potentially malicious sites, likely for phishing or malware distribution. No scripts were extracted, but the PDF's nature points towards a social engineering attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://synerhu.ru/uplcv?utm_term=subject+for+sending+resume+email PDF link annotation
    • http://hoachathoanggia.com/userfiles/file/55612578626.pdfIn PDF document text
    • http://www.eatvirukai.lt/uploads/files/52721081906.pdfIn PDF document text
    • https://afayl.com/userfiles/file/niwebewibazugaxaxu.pdfIn PDF document text
    • http://www.patriarca-batiment.com/ressource/site-image/files/girefivimi.pdfIn PDF document text
    • https://truongthanhco.vn/webroot/img/files/4561183923.pdfIn PDF document text
    • http://tradotel-riviera.com/file/vojomafopagilesefos.pdfIn PDF document text
    • https://acrgroup.nl/userfiles/file/voviwoselumob.pdfIn PDF document text
    • http://hosungtour.com/FileData/ckfinder/files/20210912_33F14B86AB99686F.pdfIn PDF document text
    • http://henghuitong.com/jingkelun/userfiles/files/20210920083819.pdfIn PDF document text
    • http://hanhthien.net/uploads/file/94734269346.pdfIn PDF document text
    • https://www.bakkersvlaanderen.be/resources/plugins/ckfinder/userfiles/0/files/xosegajanipaputewa.pdfIn PDF document text
    • http://smolninskayahotel.com/userfiles/file/dedurexatofavewovabogo.pdfIn PDF document text
    • https://vetregistr.com/ckfinder/userfiles/files/surozelado.pdfIn PDF document text
    • http://sklepjola.pl/userfiles/file/77867242197.pdfIn PDF document text
    • https://sierrainstruments.cn/fckeditor/editor/filemanager/connectors/php/fckeditor/upload/202109/file/78483699221.pdfIn PDF document text
    • http://mastervin.ru/files/file/rutadefufokolorewalulewa.pdfIn PDF document text
    • http://elma1.ru/!upload/files/jupusitoxubofaronuvuterij.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140ba6f86895---70241497625.pdfIn PDF document text
    • http://pericosrentcar.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1613c01b36d10d---69204046559.pdfIn PDF document text
    • https://sproname.com/files/userfiles/files/sagakugesajurakulew.pdfIn PDF document text
    • http://pet.nfe.go.th/m_site/ckfinder/userfiles/files/deruvozowododufulupedo.pdfIn PDF document text
    • https://vwb.mrv-educationservices.com/content_file/files/zosejaturojigetirazumisek.pdfIn PDF document text
    • https://searchlink.org/userfiles/file/jefoxoni.pdfIn PDF document text
    • http://oppedisanorobertosrl.com/userfiles/files/17865411770.pdfIn PDF document text
    • http://parbatsamajjapan.com/img/files/files/pezefisagasegulozixajaze.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_off0000df89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF89 18544 bytes
SHA-256: 99c1034541b034677532696e636de54f792a858fa0b571a1c2a635ee7c3c3737
font_01_sfnt_off00010f79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F79 11264 bytes
SHA-256: 5bf118c02c4762cf0955c74e0fe7cac2d84fd892fead0245d992bfee7db6807d
font_02_sfnt_off000129a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129A0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1