Malicious PDF — malware analysis report

Static analysis result for SHA-256 ae57b9b96ebc845a…

MALICIOUS

PDF

80.8 KB Created: 2021-09-20 05:34:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 7d5ce58f7add79f836548712bcf6c9ba SHA-1: 0d9590c78cbd3f9da9cd6c3fa5107b465b58986b SHA-256: ae57b9b96ebc845a28490f96be58341e86d306f9384e3907fcbea039484cfe46
126 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm with numerous external URIs, suggesting a phishing or malware distribution scheme. The document body is heavily obfuscated, preventing analysis of its specific content, but the presence of many links points to an attempt to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://stopserv.ru/files/file/kisunovat.pdf In PDF document text
    • http://cctsw.net/whly/up_files/FCK/file/20210907_001751_137.pdfIn PDF document text
    • https://ncltandatbar.com/home/ncltandat/public_html/dowalumniusa/ckfinder/userfiles/files/62225452723.pdfIn PDF document text
    • https://www.psk.com.au/application/third_party/ckfinder/userfiles/files/gigizopexijede.pdfIn PDF document text
    • http://yoshitomo-kokubunji.com/jcfiles/file/82636226789.pdfIn PDF document text
    • https://wegofa.com/userfiles/file/89458888357.pdfIn PDF document text
    • http://s-privod.ru/userfiles/file/72657475138.pdfIn PDF document text
    • http://webspace.mysdam.net/images/newsletter/files/kumaliwezuruzovidof.pdfIn PDF document text
    • http://westpakusa.com/phpsites/vertical_living/uploads/file/27926730742.pdfIn PDF document text
    • http://moskvaznaet.ru/upload/files/duzugapi.pdfIn PDF document text
    • https://nikolsbeauty.com/webroot/f/uploads/file/bugokim.pdfIn PDF document text
    • http://tdsns.ru/userfiles/file/xamotufijojesaxogonuwive.pdfIn PDF document text
    • http://cerrutistudio.eu/userfiles/files/33220086167.pdfIn PDF document text
    • http://pro-group.ru/userfiles/file/tufixezafopebine.pdfIn PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/hcue1qp194n1dd0pl742hvcnrc/27516189502.pdfIn PDF document text
    • http://www.mmd.ntou.edu.tw/ckfinder/userfiles/files/motoworuvidipuvopowoba.pdfIn PDF document text
    • https://arnetbilgisayar.com/upload/ckfinder/files/bunelifubidapuwedugavenal.pdfIn PDF document text
    • http://kerekesvillszer.hu/UserFiles/file/bupanuteka.pdfIn PDF document text
    • http://purofirstli.com/userfiles/files/76138880835.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613be9684b780---tabenodonizokebamaxopope.pdfIn PDF document text
    • https://ietc-oman.saktoon.com/userfiles/files/4400330942.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=video+movie+apps+downloadPDF link annotation
    • https://cakamuzejs.riga.lv/ckfinder/userfiles/files/semetoxepawirajamexopixe.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_off0000d7ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7ED 10476 bytes
SHA-256: 90de3774d2f8c3992f8e3b719c6d683702802ce74eb78497edc2e3ba68f80f45
font_01_sfnt_off0000efb4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFB4 17920 bytes
SHA-256: 2bad2dc05ffc6bb8f8f4db73746c8f89e3c5777aee2303b326a597252e360151
font_02_sfnt_off00011d9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D9B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1