Malicious PDF — malware analysis report

Static analysis result for SHA-256 298c2ff6f3e7cc97…

MALICIOUS

PDF

73.0 KB Created: 2021-09-12 21:10:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a0eccb337c93ef11b408b90f410301b2 SHA-1: 5350d754a4aebf08d12218ee23cd868b9b7261c7 SHA-256: 298c2ff6f3e7cc9740cf679c49ec6cf4d52da89ef83ac31f545989272b864bcb
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains embedded JavaScript and numerous links to external PDF files hosted on disposable domains, indicating a phishing or malware distribution attempt. The presence of embedded JavaScript suggests it may be used to exploit vulnerabilities or redirect the user to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://synerhu.ru/uplcv?utm_term=custom+rom+mi+a1 PDF link annotation
    • http://szakkepzosiklos.hu/upload/file/pipukifiwojugivajejufuso.pdfIn PDF document text
    • http://ambulatorioveterinariovianello.eu/userfiles/files/pasedozusejumusukekegoxi.pdfIn PDF document text
    • http://www.mattig-accounting.bg/fisiere/file/pewefovogivete.pdfIn PDF document text
    • http://dydlhx.com/upfiles/file///fedejifivaneru.pdfIn PDF document text
    • http://gruppocreta.com/userfiles/files/gigadenivelovo.pdfIn PDF document text
    • https://tresonance.org/uploadfiles/57306014642.pdfIn PDF document text
    • https://bursakaynak.net/userfiles/file/jalisopup.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/16136261c599a4---28342232970.pdfIn PDF document text
    • http://classiccar-jp.com/js/upload/files/pakedikozujo.pdfIn PDF document text
    • http://luckdidea.com/ckfinder/images_store/files/pedufumewozulofubafuv.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c705b9a7b7---jinipavabed.pdfIn PDF document text
    • http://qianxi.cn/filespath/files/20210910235639.pdfIn PDF document text
    • http://siamsnail.com/media/userfiles/files/vemesuvogusazupeze.pdfIn PDF document text
    • https://auto826.vnpec.xyz/uploads/files/buduvetajarulovuruboga.pdfIn PDF document text
    • http://yongqingtech.com/d/files/vikisapomixijas.pdfIn PDF document text
    • http://riviera.az/userfiles/file/sagulibebewi.pdfIn PDF document text
    • http://melodylavernebettencourt.com/media/file/bemuvakizuxoz.pdfIn PDF document text
    • http://saconsultancy.com/userfiles/file/11841557829.pdfIn PDF document text
    • https://eminenceconstruction.ca/viking1/uploads/files/bubutotipizadabo.pdfIn PDF document text
    • http://harrodsrentacar.com/public_html/userfiles/file/bujuvolewiborunitisepow.pdfIn PDF document text
    • http://rama-sp.com/rama/webroot/js/ckfinder/userfiles/files/96979846681.pdfIn PDF document text
    • http://hanhthien.net/uploads/file/54731582263.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_off0000bc1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC1F 17012 bytes
SHA-256: a34e14836314bef4f4356cd54b94a33b911f5ba86d53a2e063cc55422ff9a70a
font_01_sfnt_off0000e7db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7DB 10172 bytes
SHA-256: 2acb33805c5f8c120efcef33480724b83a59bfc077bd6d37921b9111249fa362
font_02_sfnt_off0000feb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEB9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1