Malicious PDF — malware analysis report

Static analysis result for SHA-256 855a19bb542327a1…

MALICIOUS

PDF

81.8 KB Created: 2021-09-13 10:01:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 0406a95ad0a1e42ce1bcfe5a0469d88d SHA-1: 310dd369d27839a529dda37a94d2d3544711cf50 SHA-256: 855a19bb542327a17e69119059a26cf07b52ef9522879f1f6826d24a41e57f44
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected as malicious by ClamAV and an ML classifier. It contains embedded JavaScript and numerous external URIs, suggesting it is designed to redirect users to potentially malicious websites. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a large number of links pointing to disposable hosting, reinforcing the phishing or malware distribution intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://www.performhabitat.fr/bundles/astadmin/js/ckfinder/userfiles/files/46145335399.pdf In PDF document text
    • http://nutranghongngoc.com/media/ftp/file/99946365886.pdfIn PDF document text
    • https://seltec.io/images/uploads/files/figejupumexetibe.pdfIn PDF document text
    • https://aurorabersinar2.com/contents/files/vuvibixuxewib.pdfIn PDF document text
    • http://yogathoitrang.com/quangbasanpham/app/webroot/upload/image/files/78525564852.pdfIn PDF document text
    • http://erbamedica.org/userfiles/files/bisigazu.pdfIn PDF document text
    • https://amatnieks.lv/pictures/image/23445169315.pdfIn PDF document text
    • http://thewhitmerlawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/lokenafakakegodetozul.pdfIn PDF document text
    • http://studiolaviano.it/userfiles/files/nepaxefijufebuvi.pdfIn PDF document text
    • http://softtox.com/new/userfiles/file/sifumenisixeponixiw.pdfIn PDF document text
    • http://skogsformedling.se/bilder_umeny/File/mabuz.pdfIn PDF document text
    • http://scandirent-new.ru/uploads/assets/file/nazagijizijumu.pdfIn PDF document text
    • http://ccadl.com/files/20210905050731.pdfIn PDF document text
    • http://associatedreclaimed.reclaimedoils.com/userfiles/files/18109133729.pdfIn PDF document text
    • http://gryfarmerskie.pl/pliki_wyswig/files/gixexugeg.pdfIn PDF document text
    • https://thietbivesinhsonhoa.com/webroot/img/files/bisep.pdfIn PDF document text
    • http://www.slappedtogether.com/editoruploadfiles/file/85653861115.pdfIn PDF document text
    • http://simoncaulkin.com/images/94238418052.pdfIn PDF document text
    • http://itfkarnataka.com/cvsprojects/SSK/Source/2.0.0/images/files/52652999282.pdfIn PDF document text
    • https://luxm.pl/userfiles/file/68964535541.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161362672d4d5f---7865926176.pdfIn PDF document text
    • http://chemonova.com/FCKeditor/file/gawogid.pdfIn PDF document text
    • http://fxmeat.com/upload/file/7f1b5824479dfc4028466cec67be7a31.pdfIn PDF document text
    • http://iiiemjobs.com/FCK_Editor_Images/files/pafomesapomisupusubug.pdfIn PDF document text
    • https://cubic.is/userfiles/file/najirizekuvoxofitedesosow.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=vidmate+apk+all+video+downloaderPDF 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_off0000da52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA52 10596 bytes
SHA-256: 3956020943a1b729128fd3ef345c8ff2ab92245a7ba9509f940585a6367155d7
font_01_sfnt_off0000f279.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF279 18032 bytes
SHA-256: f0dce86ad78bdba7e2b111b1e710dcb0d1cd7f7a5021a59e270e415f9c632e06
font_02_sfnt_off000120fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120FB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1