Malicious PDF — malware analysis report

Static analysis result for SHA-256 6a000a615a9b9ccf…

MALICIOUS

PDF

69.7 KB Created: 2021-09-11 02:27:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 08f4918e927f7e49b287cb28b7f43c32 SHA-1: c1f7378e4ddd25333584bc25ce215a8f4cc8ae57 SHA-256: 6a000a615a9b9ccf230591c89ec80a0e26436acab68bc73a78cc043a7ac2bbe7
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to other PDF files hosted on disposable domains, indicating a link farm designed to obscure the ultimate destination. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, suggesting a tactic to evade detection by distributing malicious content across many low-reputation hosts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://mixline.ru/img/lib/file/70881986074.pdf In PDF document text
    • http://erdbau-rauch.at/bunesijaxejadumozatakese.pdfIn PDF document text
    • http://palami.by/images/file/birinulaluv.pdfIn PDF document text
    • http://duetsepolno.pl/userfiles/file/goxejugele.pdfIn PDF document text
    • https://wangwangcamp.com/uploads/files/202109031253589378.pdfIn PDF document text
    • http://malagi.pl/user-files/fck/file/12985809517.pdfIn PDF document text
    • http://odontotecnicacoop.it/userfiles/file/17060107808.pdfIn PDF document text
    • https://branchennachweis.eu/userfiles/file/rizug.pdfIn PDF document text
    • http://avvocato-callegaro.it/public/file/98327020751.pdfIn PDF document text
    • http://highspiritsmusic.com/ckfinder/userfiles/files/joruk.pdfIn PDF document text
    • https://bluetact.com/ckfinder/userfiles/files/muzojujagudes.pdfIn PDF document text
    • https://themodernla.com/wp-content/plugins/super-forms/uploads/php/files/cf6ace637591ca758db1782aabd4f45a/jejifupewuvagaki.pdfIn PDF document text
    • http://katela.net/userData/board/file/33118033215.pdfIn PDF document text
    • http://avandcie-energy.fr/ckfinder/userfiles/files/46915040972.pdfIn PDF document text
    • http://asbu.net/uploads/FCK_files/file/tuzuk.pdfIn PDF document text
    • https://pezenasenchantee.fr/userfiles/file/segidofo.pdfIn PDF document text
    • https://taevlingar.se/images/pages/file/41836178962.pdfIn PDF document text
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161314a57cae40---34982547543.pdfIn PDF document text
    • http://greddy.com/admin/common/ckfinder/userfiles/File/2010575045.pdfIn PDF document text
    • http://mcenterdk.ru/fck_editor_files/files/79543086949.pdfIn PDF document text
    • http://morebricks.com/ckfinder/userfiles/files/87600692064.pdfIn PDF document text
    • http://mutamobilya.com/images_upload/files/83345906711.pdfIn PDF document text
    • https://xtrafitcoaching.com/www/images/files/xumefu.pdfIn PDF document text
    • https://yingzhaoliuart.com/upload/file/tepinafujemupufuvarobil.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=hide+text+conversations+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_off0000b41c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB41C 14636 bytes
SHA-256: 55c1a556c18f3c723f845793a455323ffbca8fd4935c668422e9d80a4c393437
font_01_sfnt_off0000d8e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8E7 10476 bytes
SHA-256: c37288e1f703344e8a0081b841b52ba585ab17d3f0ede9b4285dd6df9c6a74be
font_02_sfnt_off0000f0d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0D9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1