Malicious PDF — malware analysis report

Static analysis result for SHA-256 cacd0143192e85e0…

MALICIOUS

PDF

75.4 KB Created: 2021-09-08 13:07:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: af2bf76817693d3f01f6a2d17e257492 SHA-1: ae6e7c9cb0b37f58665632566edfa3c37658ab2f SHA-256: cacd0143192e85e0087dc8fd7aec9c58c5dd707192dd83fdf16b3c052460e83c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous external URIs, with one pointing to a disposable domain ('http://maxbrio.kr'), suggesting a link farm or phishing lure. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this, indicating an attempt to obscure the true destination or host a malicious payload on a temporary site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 5

  • 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.
  • 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://maxbrio.kr/files/files/64780151982.pdf In PDF document text
    • https://glbtrader.com/userfiles/file/68096735538.pdfIn PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/161304ce5e5447---70600160051.pdfIn PDF document text
    • https://gogreenonline.net/userfiles/image/fckeditor/file/vuwam.pdfIn PDF document text
    • http://mrcubezpieczenia.pl/app/webroot/media/files/21611067819.pdfIn PDF document text
    • https://zippy-inc.com/app/webroot/userfiles/files/27610602920.pdfIn PDF document text
    • https://qualitygums.com/userfiles/file/beliwixegepowev.pdfIn PDF document text
    • http://artdealer.vn/upload/fckimagesfile/efdeb65402e7657f7297fb7e2eed43e8.pdfIn PDF document text
    • http://kagoshimakojintaxi.com/userfiles/file/bozalomig.pdfIn PDF document text
    • https://agri-mal.pl/userfiles/file/34443756196.pdfIn PDF document text
    • https://vyrukrc.lt/userfiles/file/79434605561.pdfIn PDF document text
    • https://patriciobanados.cl/upload/file/In PDF document text
    • http://strandedtattoo.net/file/nopurefamo.pdfIn PDF document text
    • http://www.greenfield-sustainability.com/images/files/bebazaketururanusizefit.pdfIn PDF document text
    • http://kolbiko.com/images/uploads/file/24348284164.pdfIn PDF document text
    • https://tonymusic.se/UserFiles/files/nitewis.pdfIn PDF document text
    • http://gezond-trakteren.nl/kasteel-doornenburg-img/bestandenfile/52584166619.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/keirqrtp7b2rbrtp407q29vjct/wivewojev.pdfIn PDF document text
    • http://rooptex.com/uploads/mabazizoxutu.pdfIn PDF document text
    • http://jvcc.cn/ckfinder/userfiles/files/210902154432437549kyxwl.pdfIn PDF document text
    • http://aibasavar.edu.bd/app/webroot/ckfinder/userfiles/files/midelixi.pdfIn PDF document text
    • http://www.cpiequipos.com/assets/images/user_files/files/83412053241.pdfIn PDF document text
    • http://playitdirect.ca/ckfinder/uploadfiles/files/36765335726.pdfIn PDF document text
    • http://szao-spb.ru/images/news/file/putuvasefosasepefovexu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=ryobi+pole+pruner+manualPDF 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_off0000c532.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC532 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD49 10544 bytes
SHA-256: f4d3c4b59ea4e914dd7f7c044a3a2fd7458d3be3f699f6c9943c84f969239ec8
font_02_sfnt_off0000f502.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF502 17036 bytes
SHA-256: bf754013317d0e47ca99a2451bdce5aa86011a1592209cdd712581bb656b79f5