Malicious PDF — malware analysis report

Static analysis result for SHA-256 e1f83982d8cefa48…

MALICIOUS

PDF

81.0 KB Created: 2021-09-09 13:36:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 77352b83671abcc7e9292847034d3a76 SHA-1: 5197c5e90c4ba04c1b71e640dffae8ddd93679f1 SHA-256: e1f83982d8cefa48202914b1af0c900df9c7d49784d7fbb2439f066afb6dccd9
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains embedded JavaScript and a large number of external URIs hosted on disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of embedded JavaScript indicates an attempt to execute code, likely to download further payloads or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://smidgel.ru/uplcv?utm_term=extract+img+file+android PDF link annotation
    • https://fundacionamigosdelmarcaribe.ong/ckfinder/userfiles/files/32728662424.pdfIn PDF document text
    • http://grandrosso.com/js/upload/files/74652371011.pdfIn PDF document text
    • http://www.jacenter.org/js/ckfinder/userfiles/files/80165093558.pdfIn PDF document text
    • http://feminella.ro/upload/fck/55155753805.pdfIn PDF document text
    • http://taxplus.in/images/contentimages/files/98944315657.pdfIn PDF document text
    • http://tunesistudio.eu/userfiles/files/96441416518.pdfIn PDF document text
    • http://oipipleszno.pl/userfiles/file/73141347051.pdfIn PDF document text
    • http://centroolosprato.it/userfiles/files/ramogakubazup.pdfIn PDF document text
    • http://doubles301.jp/files/ckeditor/files/19054399935.pdfIn PDF document text
    • https://alexspa.pl/userfiles/file/39929305786.pdfIn PDF document text
    • http://tfh-filter.hu/_user/file/37715747006.pdfIn PDF document text
    • http://autoset66.ru/admin/ckfinder/userfiles/files/digojaj.pdfIn PDF document text
    • http://trivio.it/userfiles/files/40523204306.pdfIn PDF document text
    • https://www.sahabatkeluargahomecare.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f152f9e8f4---nibolexemuleditizikoga.pdfIn PDF document text
    • https://makanbanyak.net/contents/files/94587202940.pdfIn PDF document text
    • http://senseoftourism.dk/userfiles/file/jonawav.pdfIn PDF document text
    • http://thunderstar.cn/userfiles/file/20210906031141741825893.pdfIn PDF document text
    • http://winecellarkeeper.com/ckfinder/userfiles/files/55874034848.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/161374a5f79ebe---33328254798.pdfIn PDF document text
    • https://editora-arara-azul.com.br/site/admin/ckfinder/userfiles/files/nuzanisox.pdfIn PDF document text
    • http://globalbando.com/DATA/upload/files/202109060744249019.pdfIn PDF document text
    • http://erisalaw-chicago.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/95392238922.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_off0000d708.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD708 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF1F 10736 bytes
SHA-256: f87466fe3cd2fe4d657fbfb9c73b6cdc08305f6797466914ee48c50f3093943d
font_02_sfnt_off00010793.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10793 17816 bytes
SHA-256: 3aa3735f0a2ef72c4cd94d461f0d86eefec26ce37f97b1433a16ca481e61ff24