Malicious PDF — malware analysis report

Static analysis result for SHA-256 ece51a31cc7417d9…

MALICIOUS

PDF

88.3 KB Created: 2021-09-19 21:36:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 4592a0d4af17059832bcc2f945f1adf0 SHA-1: 13b786d93fcb8098a5d231f660dd8c16d72679d9 SHA-256: ece51a31cc7417d9914a8ee47e439558d8786a7f7e384003f0640013ee218aea
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 suspicious PDF files on various domains. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic indicates a deliberate attempt to create a large number of links, likely to obscure malicious activity or distribute further payloads. The ML classifier and ClamAV detection strongly suggest malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://doxetrilinh.com/media/ftp/file/zovemuwuxabakupakufubas.pdf In PDF document text
    • https://perfecthospitals.org/FCKeditor/file/jefijalogixegiwanupokajo.pdfIn PDF document text
    • http://safiorida.nl/operatori/userfiles/file/jafobuv.pdfIn PDF document text
    • https://contemporaryteas.in/admin/uploads/file/74297462112.pdfIn PDF document text
    • http://xn----otbb6ahq3d.xn--p1ai/ckfinder/userfiles/files/7955572722.pdfIn PDF document text
    • http://kronikarp.pl/ckfinder/userfiles/files/gifiro.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16139d362c185a---romufeda.pdfIn PDF document text
    • http://kunmobile.vn/files/uploaded/20210908/file/82684079423.pdfIn PDF document text
    • https://yaofangpeixun.com/upload/files/23593119280.pdfIn PDF document text
    • http://claudiamelchior.it/images/file/fawesomexibuxogifojanumo.pdfIn PDF document text
    • https://tvmreza.tv/ckfinder/userfiles/files/35556686306.pdfIn PDF document text
    • https://www.barefoothoa.com/webroot/js/ckfinder/userfiles/files/ruton.pdfIn PDF document text
    • http://arablift.net/userfiles/file/munugakilodorulewodesetu.pdfIn PDF document text
    • https://sieuthimaycafe.vn/uploads/file/78475116579.pdfIn PDF document text
    • http://ozhelalikram.de/resimler/files/80506225584.pdfIn PDF document text
    • http://ckm-machinery.com/userfiles/files/3977487979.pdfIn PDF document text
    • http://umrllc.com/userfiles/files/4116616773.pdfIn PDF document text
    • http://gzbaosui.com/uploadfile/files/texuxarofuxan.pdfIn PDF document text
    • http://aksaaydinlatma.com/img/editor/image/file/komapet.pdfIn PDF document text
    • http://amkchem.com/upload/files/gasesizironenodufulajoxik.pdfIn PDF document text
    • http://misterholidaysanprisco.it/userfiles/files/2941135663.pdfIn PDF document text
    • http://thingsantiquesla.com/userfiles/files/22567404559.pdfIn PDF document text
    • http://uktohabbarijamalta.com/files/file/40679127319.pdfIn PDF document text
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f3ef1bcc99---3479090782.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=how+to+transfer+photos+to+mac+from+androidPDF 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_off0000f21b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF21B 18560 bytes
SHA-256: 73480413563beac9cbb5eab1953d3b08b81f3e18a4dd621bea6ce232e73edbc7
font_01_sfnt_off0001220d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1220D 10916 bytes
SHA-256: 1469c7401415eca1cb1d4cb52e1d59b011a96592819cb072dc375a95a0426378
font_02_sfnt_off00013b27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B27 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1