Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b39bdc8b7ae93c5…

MALICIOUS

PDF

87.4 KB Created: 2021-09-10 13:35:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 881a62ab31316dd1431090f875397cfa SHA-1: 98953e9c25f1a95618508df91b1fb76e3e751847 SHA-256: 4b39bdc8b7ae93c500a4347bc7cfebd59c97521efcf349fbdf862c9b1a3182df
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to link farms on disposable hosting. The ML classifier and ClamAV detection strongly indicate maliciousness. The embedded JavaScript likely facilitates the redirection to these external links, which are characteristic of phishing or malware distribution schemes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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
  • 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://tnmkor.com/FileData/ckfinder/files/20210903_A89967622505373C.pdf In PDF document text
    • https://dildendilecevirievi.com/upload/ckfinder/files/jazuxusudilot.pdfIn PDF document text
    • https://capital-publishing.com/ckfinder/userfiles/files/zowutovezuzosapak.pdfIn PDF document text
    • https://nakipoglugroup.com/upload/ckfinder/files/nawunitomejezizemolirov.pdfIn PDF document text
    • https://mattress-leader.com/media/xiburotebopa.pdfIn PDF document text
    • https://alexandrapanayotou.com/web/images/static/file/39053261769.pdfIn PDF document text
    • https://senzedigicraft.com/wp-content/plugins/super-forms/uploads/php/files/221a2c223ad0a521ee023b90a4339b1b/pejejokopigupazositineta.pdfIn PDF document text
    • http://woodwork.pl/ubezpiecz/obrazy/file/siluvaviluwifow.pdfIn PDF document text
    • http://animationcoach.com/userfiles/file/rudalesujiro.pdfIn PDF document text
    • http://ppfi-online.com/userfiles/file/dulinopunebigejupox.pdfIn PDF document text
    • http://uhy-th.com/image/upload/files/sitifafozebifaxa.pdfIn PDF document text
    • http://ckrestaurantgroup.com/ckfinder/userfiles/files/7248829304.pdfIn PDF document text
    • http://dermatologomiguelgallego.com/miguel/fck/file/84463235295.pdfIn PDF document text
    • http://evolution-dev.com/file_media/file_image/file/tibepij.pdfIn PDF document text
    • http://jiji.pgo.tw/pic/uploads/files/67531122024.pdfIn PDF document text
    • https://holocaustresearch.pl/nowy/photo/file/21314581201.pdfIn PDF document text
    • http://rama-sp.com/rama/webroot/js/ckfinder/userfiles/files/wivipivagodururirumibap.pdfIn PDF document text
    • http://quick-thailand.com/images/uploads/file/3160564535.pdfIn PDF document text
    • http://trips-in.com/ckupload/files/55377275346.pdfIn PDF document text
    • http://albarossa.jp/js/upload/files/ponevuwagek.pdfIn PDF document text
    • http://singlesync.com/userfiles/file/pabokizerujizotanipusud.pdfIn PDF document text
    • http://bojovesporty.cz/userfiles/file/megusozafijafomulifuneve.pdfIn PDF document text
    • http://gdlejia.com/uploadfile/files/20210903_125652.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=flash+fox+appPDF link annotation
    • 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_off0000f1d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1D2 10008 bytes
SHA-256: 4f9f8f8733f357a7979a1b259513971a887621595be560a44065460f93f2eb02
font_01_sfnt_off0001082d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1082D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001203f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1203F 18272 bytes
SHA-256: 86e74eac7e07bc247eba8042bdb2ccab84e3348e9a8451b5d2743fe525517aff