Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4853a899aa5dfaa…

MALICIOUS

PDF

90.4 KB Created: 2021-09-18 17:15:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 59762c8b16dd0ff3d396373da1021644 SHA-1: f9741383ac1d9b8d611a730915abdbd3a7e3bc36 SHA-256: b4853a899aa5dfaa088633075509a996fd4b79dd696e6090c3891e5f316ab7d6
134 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a high number of external URIs, many of which point to disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or a link farm for SEO manipulation. The embedded JavaScript is likely used to facilitate the redirection or obfuscate the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://giraffeng.net/infodaily/gen-ckfinder/userfiles/files/2118944728.pdf In PDF document text
    • http://korytnica.net/data/files/96394138060.pdfIn PDF document text
    • http://teedinmaesai.com/user_img/file/64706561751.pdfIn PDF document text
    • http://nhasachnguyenvancu.com/Images_upload/files/73631948426.pdfIn PDF document text
    • http://dobraukraina.org/sites/all/sites/dobraukraina.org/files/77776566276.pdfIn PDF document text
    • http://metalltechnik-kutschi.at/28617412047.pdfIn PDF document text
    • http://www.brickchamber.com/ckfinder/userfiles/files/12405741540.pdfIn PDF document text
    • https://brincandoeaprendendo.com/fotosempresa/files/27374656109.pdfIn PDF document text
    • http://www.saaegfpolis.org.br/ckfinder/userfiles/files/83525743117.pdfIn PDF document text
    • https://arendic.cl/files/pujubife.pdfIn PDF document text
    • http://ain.proximeo.com/ckfinder/userfiles/files/61302641054.pdfIn PDF document text
    • http://edu-soft.ru/site/htmlimages/file/wesugufijoxutosisesapigi.pdfIn PDF document text
    • http://gyogytornasz.hu/editor_up/37836273224.pdfIn PDF document text
    • https://ehbo-oostkapelle.nl/userfiles/file/jagasiguvu.pdfIn PDF document text
    • https://curewelldiabetes.com/userfiles/file/xudevigewaluseluja.pdfIn PDF document text
    • http://phuongdonggolf.vn/app/webroot/uploads/files/lizevirekebawig.pdfIn PDF document text
    • http://conhantaoankhanh.com/webroot/img/files/86627339216.pdfIn PDF document text
    • http://pixel-pro.ru/upload/file/rexeminunesuzezakirol.pdfIn PDF document text
    • https://consurs.ro/ckfinder/userfiles/files/27536999032.pdfIn PDF document text
    • http://stfurnimart.com/file_media/file_image/file/vepojasivexogiwabad.pdfIn PDF document text
    • http://masterref.ru/editorfiles/file/levogezejumudaxivevur.pdfIn PDF document text
    • http://cathyourhair.nl/js/ckfinder/userfiles/files/welixibilutimusoxezobut.pdfIn PDF document text
    • http://heizler.hu/files/file/50502428798.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=angrist+and+pischke+mostly+harmless+econometricsPDF 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_off0000f8b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8B5 18944 bytes
SHA-256: 34c5ff210f95fb8aab8010474bb44473f62967dd4b358b1dae73daf244680062
font_01_sfnt_off000129cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129CC 11148 bytes
SHA-256: ea98c50919080da4e7da1c5ba981461ad7c4d888ac73ca7eee657c162d0b7beb
font_02_sfnt_off00014382.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14382 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1