Malicious PDF — malware analysis report

Static analysis result for SHA-256 b848d3f9dbccf138…

MALICIOUS

PDF

87.1 KB Created: 2021-09-08 16:21:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c6cf07d3465a0dffd758f73668aedd40 SHA-1: b533d9407c12f8ad0671e02fde10ff045510a8a6 SHA-256: b848d3f9dbccf138a5bbf44ae89d588ce883bab997083ddbccb5625a85f86a44
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was identified as malicious by a ML classifier and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, containing numerous embedded URLs that redirect to external PDF files, suggesting an attempt to distribute further malicious content or conduct phishing. While no scripts were directly extracted, the PDF structure and embedded URLs are indicative of a malicious intent to lure users to compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 5

  • 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.
  • 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://patanamachine.com/imgUpload/files/bedomumijukujufisif.pdf In PDF document text
    • http://stellar-toys.com/ckfinder/userfiles/files/39436539487.pdfIn PDF document text
    • http://arredamentoambienti.it/img/file/folofodenu.pdfIn PDF document text
    • https://lotte-ppta.com/beta/assets/file/52042961693.pdfIn PDF document text
    • http://vetcasatenovo.it/userfiles/files/kovuv.pdfIn PDF document text
    • http://velocimapper.com/webfiles/file/28045462202.pdfIn PDF document text
    • http://zvaracskaskola.eu/editor_uploads/system/files/21882106117.pdfIn PDF document text
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/161371ca1e2551---bagul.pdfIn PDF document text
    • http://klwas.org/userfiles/images/file/tijiwemozejaxurajumama.pdfIn PDF document text
    • http://linpus.com/app/webroot/userfiles/files/xikuf.pdfIn PDF document text
    • http://bilmatbasim.com/userfiles/file/13870409011.pdfIn PDF document text
    • http://taeguektour.com/FileData/ckfinder/files/20210903_6C09183F7AE9EE43.pdfIn PDF document text
    • http://solarexperte.ch/fckeditor/editor/images/file/wenosifuk.pdfIn PDF document text
    • http://agecarekorea.com/ckupload/files/jazibufetivanitove.pdfIn PDF document text
    • http://ingfrimale.com/userfiles/files/62268837730.pdfIn PDF document text
    • https://nevjegyzek.eu/uploads/file/peworelekemufiweko.pdfIn PDF document text
    • http://flapboxes.custompackageboxes.com/userfiles/files/1490604596.pdfIn PDF document text
    • http://alltechsro.cz/files/lojizuxudasinepumit.pdfIn PDF document text
    • http://bippex.com/filespath/files/20210907200433.pdfIn PDF document text
    • http://mylodge-naoshima.com/52074225577.pdfIn PDF document text
    • http://intranet.uts.edu.co/portal/app/ckfinder/userfiles/files/saxoxogival.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/170748babe2d30b30bb9921677cd96bb/39518915802.pdfIn PDF document text
    • https://grafconsulting.pl/Upload/file/21737407605.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=acsm%27s+advanced+exercise+physiology+pdfPDF 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_off0000ed1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED1E 11268 bytes
SHA-256: 5d15f813246ddba6b1fe9455252c054cf3e7c7e3dffbfd10a7e91b2f5df1c288
font_01_sfnt_off0001073c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1073C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011f4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F4E 18156 bytes
SHA-256: da8b18f016ca115fbe1fa31eb9ef19e79f02e315a30ff6aa9ca8d6ad0cde73c3