Malicious PDF — malware analysis report

Static analysis result for SHA-256 da6744b854053250…

MALICIOUS

PDF

79.8 KB Created: 2021-09-08 15:18:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: f613049fd209dbe80c4e060cb2303d44 SHA-1: 71c7041ba889e3913a9ca15cd1661172cc6dad1b SHA-256: da6744b8540532507db2a6a12973baf26c58229574d63ea94cbd7c3a26802c9d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URLs, many of which are part of a link farm hosted on disposable domains, indicating a phishing or malware distribution attempt. The ClamAV detection and ML classifier strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 https://drafthe.ru/uplcv?utm_term=combine+multiple+pdfs+into+one+windows+10 PDF link annotation
    • http://medical-1669.com/userfiles/files/gorezagikojoloxababisop.pdfIn PDF document text
    • https://maturana.cl/upload/file/4168938677.pdfIn PDF document text
    • http://studioguidobarbieri.it/userfiles/files/88321359596.pdfIn PDF document text
    • https://majubesar.org/contents/files/11482969515.pdfIn PDF document text
    • https://www.area-tlc.com/public/ckfinder/userfiles/files/36045258852.pdfIn PDF document text
    • https://408of53crownstreet.com/assets/media/files/5224364203.pdfIn PDF document text
    • http://ydis.kr/userfiles/file/071653453503.pdfIn PDF document text
    • http://chaodontuonglai.vn/uploads/ck_upload/files/1056683469.pdfIn PDF document text
    • https://www.sexualaufklaerung-schule.ch/ck/ckfinder/userfiles/files/rigoduvupijok.pdfIn PDF document text
    • http://blevy.com/ckfinder/userfiles/files/vunakirivojapapafonov.pdfIn PDF document text
    • http://axi-hohenstein.de/userfiles/file/tifuporo.pdfIn PDF document text
    • http://www.mustwalge.ee/data/content/files/93280219176.pdfIn PDF document text
    • https://fiscalonline.eu/app/webroot/files/userfiles/files/kobinixazozegilofupax.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/16133b7b25313e---49759510782.pdfIn PDF document text
    • http://abwvictory.com/uploads/files/nutabipu.pdfIn PDF document text
    • https://snapstudios.ca/userfiles/file/bopofemunip.pdfIn PDF document text
    • https://we-plus.tw/ckfinder/userfiles/files/11444086789.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/zegawe.pdfIn PDF document text
    • http://liccuza.ro/stiri_files/file/65996398944.pdfIn PDF document text
    • http://ruiqingchem.com/upload/files/35982467019.pdfIn PDF document text
    • https://yam-token.com/business_school/uploads/file/gujomevipobapifozukaxe.pdfIn PDF document text
    • http://youzedu.com/ckimages/files/20210904184658166467.pdfIn PDF document text
    • http://szerecsen.hu/editor_up/milevowozowiruso.pdfIn PDF document text
    • https://regenerativetherapyforpain.com/wp-content/plugins/super-forms/uploads/php/files/acda32b23de023cf56fd80ed82c6cdfc/mavalalimojafe.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_off0000d1de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1DE 18148 bytes
SHA-256: 269de53516febfe3016b578c52156b591b71b3d422c1546e7e02a49410726110
font_01_sfnt_off00010087.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10087 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001189e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1189E 10928 bytes
SHA-256: 3f57b772b1ad1d24a627b30fbd4c80263e24aff16f5bed8116066346873a983e