Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a844611c19df6bf…

MALICIOUS

PDF

80.6 KB Created: 2021-09-06 07:18:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1bb83f6b6f8402d3faee3ee4ffe03ea8 SHA-1: 6159d54625111d17d424f61e17b2fd7bfad1cd7a SHA-256: 1a844611c19df6bf8e1f40de8ef2592480aa432b5b3d906dd3f155747ef98106
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ML classifiers and ClamAV, with critical heuristic firings indicating a PDF phishing trojan. It contains embedded JavaScript, which is often used to exploit vulnerabilities or redirect users. The PDF also functions as a link farm, pointing to numerous external PDF files hosted on various domains, suggesting an attempt to obscure the ultimate destination or distribute payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 6

  • 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.
  • 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 http://apsara.ru/userfiles/file/47725020747.pdf In PDF document text
    • http://gr-chem.com/upload/files/zapuvukodamavajujanagasi.pdfIn PDF document text
    • http://alacarte-design.de/userfiles/file/26630636730.pdfIn PDF document text
    • http://sshs1962.info/clients/3/33/33dcd814b32da85629335a95ab3d0158/File/wagidiwava.pdfIn PDF document text
    • https://pjkconstruction.ca/images/file/6404605909.pdfIn PDF document text
    • http://uspeh-kursk.ru/ckfinder/userfiles/files/fojarujedofavore.pdfIn PDF document text
    • http://studiofelician.com/userfiles/files/wuvovut.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/voguduzovojulimotilelijub.pdfIn PDF document text
    • http://misr-consult.com/userfiles/file/wuzamuwufeluvilaz.pdfIn PDF document text
    • http://aelma.com/sites/default/userfiles/file/salupigoworizukobojajefon.pdfIn PDF document text
    • http://stlnsk.ru/uploads/file/zibogunafigojat.pdfIn PDF document text
    • https://tabularasa.lv/sites/tabularasa/uploads/documents/files/poneduxubulidamabig.pdfIn PDF document text
    • http://gaishachuukobuhin.com/js/upload/files/tegufomujudomonem.pdfIn PDF document text
    • http://elitaliaweb.it/upload/file/34277991632.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d35c734423---63010159135.pdfIn PDF document text
    • http://shuswapladystriders.ca/userfiles/file/wamagulibobut.pdfIn PDF document text
    • http://khacvietlaser.vn/public/images_news/files/79275216731.pdfIn PDF document text
    • https://arvikabc.com/images/uploadedimages/file/59112738080.pdfIn PDF document text
    • https://clap-bas.com/userfiles/file/zokozanorireji.pdfIn PDF document text
    • http://matstravel.ru/userfiles/file/48809222995.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/9vfgopkurgd0kpvsmpfgiike43/42593402403.pdfIn PDF document text
    • https://infotechsystemsonline.com/ital/www/img/file/vesitejonoxakovujil.pdfIn PDF document text
    • http://begemot-rus.com/uploadfiles/file/2021053003030473499.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=goldstein+classical+mechanics+2nd+edition+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_off0000d5e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5E8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000edfa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDFA 17536 bytes
SHA-256: ec50ff6b9534f0fba95009f5be4a36f09de9ad0f58feea129ff63e4499046e7b
font_02_sfnt_off00011bbb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BBB 10944 bytes
SHA-256: f26e4dc13b607ef5d0dc5bff7d1483b8cfde7fa6966f2b1c6cecb8db8d78eb17