Malicious PDF — malware analysis report

Static analysis result for SHA-256 c938b26672e23ae8…

MALICIOUS

PDF

86.0 KB Created: 2021-09-09 11:36:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 43e93082bdb467c4c372be3a849eabee SHA-1: b47e1b98b993678fa4a1c957f8eb825aa6cc402a SHA-256: c938b26672e23ae88685b4ecda646b43655b67ccdcd37332d9a92b414512d816
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a high number of external URIs, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is a common technique for exploiting PDF vulnerabilities or redirecting users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://chcial.ru/uplcv?utm_term=good+app+for+reading+manga PDF link annotation
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131098b6041b---27878522938.pdfIn PDF document text
    • http://travelport.pl/userfiles/file/pivalefamisipu.pdfIn PDF document text
    • http://advairtech.eu/assets/userfiles/file/53347851780.pdfIn PDF document text
    • http://tlumacz-lipno.pl/pdrzewiecki/files/84430675534.pdfIn PDF document text
    • http://grandp.ru/userfiles/file/dunoko.pdfIn PDF document text
    • http://caminodesantiagoenmoto.com/assets/ckfinder/core/connector/php/uploads/files/60500679102.pdfIn PDF document text
    • https://cezartravel.hu/userfiles/file/64228415876.pdfIn PDF document text
    • http://ballarioarchitetti.eu/userfiles/files/38386824060.pdfIn PDF document text
    • http://www.hgbehringer.de/img/files/files/78643962386.pdfIn PDF document text
    • https://dichocungtoi.com/userfiles/file/siwikatenajugagudoruke.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/fcceb452373813dbe7b1787b88cab889/58067953522.pdfIn PDF document text
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/161350d81c95fe---difefimulero.pdfIn PDF document text
    • http://www.jacenter.org/js/ckfinder/userfiles/files/metalituzavuxifekutibe.pdfIn PDF document text
    • https://receptabc.hu/images_banner/files/fakirinaseravapuw.pdfIn PDF document text
    • https://blugarden.eu/file/zamozeponawe.pdfIn PDF document text
    • http://decaiyun.com/upload/file/210902201633153775cylz27fxft4a.pdfIn PDF document text
    • http://rogersdesignhouse.com/uploads/files/nununufefive.pdfIn PDF document text
    • http://mdsalon.ru/img/lib/file/70726402625.pdfIn PDF document text
    • http://albino-pitti.com/pub_img/file/31152741724.pdfIn PDF document text
    • https://mavachhaiphong.com/upload/files/37161222806.pdfIn PDF document text
    • http://beijingteye.com/upload/files/24293949134.pdfIn PDF document text
    • http://wwsm-hk.com/files/file/wakazowodexurozupufe.pdfIn PDF document text
    • http://www.huescalamagiaenfotos.com/userfiles/files/fakulikebulikizude.pdfIn PDF document text
    • http://liebherr-tr.com/userfiles/file/4416013068.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_off0000ee42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE42 10568 bytes
SHA-256: d8a57c5593096912aaeb87c561bdd91b10ebeee62db389b545b0980f65775956
font_01_sfnt_off0001060e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1060E 17324 bytes
SHA-256: 7406482f6cc37633eae1a0b4715a7627a9229773fb0f67588c6d45b401614b1d
font_02_sfnt_off000132fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x132FB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1