Malicious PDF — malware analysis report

Static analysis result for SHA-256 88ff0d8dfdf86008…

MALICIOUS

PDF

70.2 KB Created: 2021-09-25 10:28:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6f718e5eb740d25264bb54a16c3c8147 SHA-1: 8b62bd9cc7cb9c74cbff6a6073c1f32e76e7334e SHA-256: 88ff0d8dfdf860082abf3a0200c6bf94c3f3b3ef329297489e0731fe1209c9fe
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as a phishing trojan and by an ML classifier as malicious. It contains numerous embedded URLs pointing to various domains, many of which appear to be link farms or disposable hosting, suggesting a phishing or malware distribution campaign. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM specifically indicates a high number of links on disposable hosting, reinforcing this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://coretry.ru/uplcv?utm_term=mame+on+android+tablet PDF link annotation
    • http://kolaykanal.com/userfiles/files/kefofosubofejemajafetag.pdfIn PDF document text
    • https://beta.nhatthiengroup.com/files/uploaded/files/63873522056.pdfIn PDF document text
    • http://faurau.com/luodan/images/userfiles/file/sadamebizumigijov.pdfIn PDF document text
    • https://learnrkb.jugalbandiresearch.com/ckfinder/userfiles/files/57426753007.pdfIn PDF document text
    • http://codienlanhtrangia.com/Images_upload/files/21130010411.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/mtvtn5qhka5e6o3t835br5nl33/14793584970.pdfIn PDF document text
    • https://gymlesgeants.com/upload/editor/file/74914331563.pdfIn PDF document text
    • http://oodow.cn/upload/file/2109031147259960903wm90hxtgc44.pdfIn PDF document text
    • http://xn--80ab1a9a.xn--p1ai/sadm_files/45496039271.pdfIn PDF document text
    • https://hoanghaie.com/Images_upload/files/kasasuzarewapisebiwumiri.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614e7358dad7f---subuzugixi.pdfIn PDF document text
    • http://minhquoc.vn/ckfinder/userfiles/files/zarasu.pdfIn PDF document text
    • http://syntrend.critical.tw/upload/files/96351153797.pdfIn PDF document text
    • http://an-professional.ru/img/files/file/buritexomuwurewev.pdfIn PDF document text
    • https://andhimazhai.com/images/files/ziwez.pdfIn PDF document text
    • http://9262895.ru/ckfinder/userfiles/files/39831439941.pdfIn PDF document text
    • http://zatoodesign.com/userfiles/files/dubimupizimaguzuze.pdfIn PDF document text
    • http://skogsformedling.se/bilder_umeny/File/munetowoxirisewifeku.pdfIn PDF document text
    • http://honeycontacts.com/uploades/userfiles/file/dabururalesep.pdfIn PDF document text
    • https://bomando.bomsolar.com/uploadfiles/files/poxaloga.pdfIn PDF document text
    • https://triatlonshop.cz/userfiles/file/82542677160.pdfIn PDF document text
    • https://fond.ru/userfiles/file/8341455340.pdfIn PDF document text
    • https://qian-ho.com/upfiles/editor/files/sukifafosavozedite.pdfIn PDF document text
    • http://prestopc.it/upload/file/70744632449.pdfIn PDF document text
    • https://floresdeserrezuela.com/aym_image/files/xemepetelujazivuvolaga.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_off0000b07f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB07F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c896.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC896 10376 bytes
SHA-256: ad2a925cb0f9e2872ca544c2959d56f3c254ff49a9277cce764f463ffe536589
font_02_sfnt_off0000dfed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFED 17180 bytes
SHA-256: 67b306c482dd341120f3d27ed48f1b0a8f1c3377faa9b81737da4dafffacacf8