Malicious PDF — malware analysis report

Static analysis result for SHA-256 b556b43a08c7c6ac…

MALICIOUS

PDF

86.9 KB Created: 2021-09-12 00:33:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 544d6f99b924a222b53b556aac39bbfa SHA-1: 388e07653adbc0d995617d05ec10f791c7c6b08b SHA-256: b556b43a08c7c6aca7e6c84c6e64ed8c2dc40a3abca208c52273ef0fc294499c
134 Risk Score

Malware Insights

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

This PDF file contains embedded JavaScript, which is a common technique for delivering malicious content. The file also includes numerous external URIs, one of which, 'https://krisoc.ru/uplcv?utm_term=us+bank+mobile+app+for+android', suggests a phishing attempt related to a mobile banking application. The ML classifier and ClamAV detection strongly indicate malicious intent, likely involving exploitation for client execution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://krisoc.ru/uplcv?utm_term=us+bank+mobile+app+for+android PDF link annotation
    • http://wronba.com/uploads/wysiwyg/file/gofopiwepagoreb.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161363b4d1601e---wudowibosikibeze.pdfIn PDF document text
    • http://www.impactit.in/ckfinder/userfiles/files/lowosapomevufufavuvabikav.pdfIn PDF document text
    • http://albarossa.jp/js/upload/files/24091966412.pdfIn PDF document text
    • https://bagstyle.uz/images/file/risesidog.pdfIn PDF document text
    • http://holzbau-napetschnig.at/73017676356.pdfIn PDF document text
    • http://taociren.com/upload/file/210908091936228252mcagvawljggt.pdfIn PDF document text
    • http://erisalaw-chicago.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/96318561401.pdfIn PDF document text
    • http://fongyoskert.hu/userfiles/files/47499528906.pdfIn PDF document text
    • https://etadelloro.it/images/file/10277957808.pdfIn PDF document text
    • http://ibookingkr.com/FileData/ckfinder/files/20210903_281269BEAA3768FE.pdfIn PDF document text
    • http://0225674989.kad.tw/kads/ckfinder/userfiles/files/99855745291.pdfIn PDF document text
    • http://koala-al.com/d/files/jogulituvaj.pdfIn PDF document text
    • https://kit-veron.my/ckfinder/userfiles/files/dobojuduvarugusepa.pdfIn PDF document text
    • http://tandprotheses.com/ckfinder/userfiles/files/netojaxekelobasogido.pdfIn PDF document text
    • http://balashixa.inhome360.ru/admin/ckfinder/userfiles/files/6788519886.pdfIn PDF document text
    • http://serenetour.com/image/upload/File/tenegor.pdfIn PDF document text
    • https://masterpieces-mallorca.com/wp-content/plugins/super-forms/uploads/php/files/5b2bddd37f787e7b27b1ce6590fa6980/vaduwubupid.pdfIn PDF document text
    • https://dananeye.com/uploads/files/202109010224494631.pdfIn PDF document text
    • https://www.q-jin.ne.jp/ckfinder/userfiles/files/kukunutexofidu.pdfIn PDF document text
    • https://daynexweb.com/upload/ckfinder/files/100577899.pdfIn PDF document text
    • https://ferest.ro/imagini_ws/93790208844.pdfIn PDF document text
    • https://nistd.in/userfiles/file/66649946602.pdfIn PDF document text
    • http://purel-biopharm.com/upload/files/goropidexapozutunixizedov.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_off0000ef81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF81 10800 bytes
SHA-256: aa0c0285bc961087a8f2cfe45fd275a563fe7393a6c6c224f69855f2937f9bd4
font_01_sfnt_off0001081c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1081C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001202e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1202E 17600 bytes
SHA-256: 44f59a41dd20e23e618589cdaa7d16b22bd8fb9073ecf5919afff88479c7569a