Malicious PDF — malware analysis report

Static analysis result for SHA-256 043b385c898ee77b…

MALICIOUS

PDF

83.6 KB Created: 2021-09-12 02:52:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 1e543f7ff01804567bc6c86fb20ca09f SHA-1: 708f4c096d9f90a6b9ee6ee677d6606bb99f934d SHA-256: 043b385c898ee77bb48db5b1ae970c45f9e73c7657e73f4e1546ff6cd2ef6d3f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many of which point to external sites that appear to be part of a link farm, suggesting a phishing or malware distribution scheme. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a strategy to obscure the ultimate destination of the links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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.
  • 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://writtenmail.com/upload_images/file/xewitekizufedup.pdf In PDF document text
    • http://orosweb.hu/ckfinder/userfiles/files/99566621770.pdfIn PDF document text
    • http://aotwresort.org/ckfinder/userfiles/files/lonixokefixapufukajid.pdfIn PDF document text
    • http://speednewslive24.com/assets/ckfinder/core/connector/php/uploads/files/45766348124.pdfIn PDF document text
    • https://volgogradexpo.ru/ckfinder/userfiles/files/genifu.pdfIn PDF document text
    • http://fotofolliasanlazzaro.it/userfiles/files/87340566198.pdfIn PDF document text
    • http://hamdannepal.com/userfiles/file/xelojuregogubugaladedavaf.pdfIn PDF document text
    • https://rumusjitu.com/contents/files/25243736944.pdfIn PDF document text
    • https://www.alugutader.fr/ckfinder/userfiles/files/85056420959.pdfIn PDF document text
    • https://mcq-exambd.com/app/webroot/ckfinder/userfiles/files/44648120260.pdfIn PDF document text
    • https://bakotech.at/uploads/ckeditor/files/95940517823.pdfIn PDF document text
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613338ed9b311---25579040726.pdfIn PDF document text
    • https://sbmhavacilik.com/userfiles/file/87904605111.pdfIn PDF document text
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/ed1d58fdd44215b0543d2f543cc124d3/zuxabetuvir.pdfIn PDF document text
    • https://stichtingech.org/ckfinder/userfiles/files/lupefalajonamagaxipipumal.pdfIn PDF document text
    • https://daaeportrett.no/upload/file/denevoni.pdfIn PDF document text
    • https://softwebstar.com/shop/userfiles/file/87006043290.pdfIn PDF document text
    • https://residenciasanamaro.es/userfiles/files/16916115173.pdfIn PDF document text
    • http://hkxhjfc.ltd/uploads/files/20210912055448.pdfIn PDF document text
    • http://www.feniuniversity.edu.bd/app/webroot/ckfinder/userfiles/files/23205611000.pdfIn PDF document text
    • https://andana.us/files/files/wanexika.pdfIn PDF document text
    • https://aadhaarretail.com/administrator/imagetemp/file/moxupixa.pdfIn PDF document text
    • http://artgraf24.pl/userfiles/file/kenaxurop.pdfIn PDF document text
    • http://vangphutai.com/images/uploads/files/kufajoravibekiluneb.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=como+jogar+jogos+em+flash+no+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_off0000df06.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF06 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f71d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF71D 10864 bytes
SHA-256: 7f6733901e330ab7054c7abe12910e82100bf3c2d7dd021190a41e33e58ae8e7
font_02_sfnt_off00010fbe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FBE 19088 bytes
SHA-256: a1a577bba6e963338ef417afb44ed2f4680b2916885a0796c9d44c9b2d5aa51b