Malicious PDF — malware analysis report

Static analysis result for SHA-256 23dc6ecddddba4f3…

MALICIOUS

PDF

73.4 KB Created: 2021-10-07 10:06:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 891ee939faa16ae8a47a8b6b15846140 SHA-1: fe002877b5245d3e499a7f7b6d400089e5353412 SHA-256: 23dc6ecddddba4f3ab2eabf651242a2c1c0e12403806c2cc50c5e82cacff6054
134 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, flagged by heuristics, which is a common technique for malicious PDFs. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded JavaScript likely facilitates the redirection to a link farm, as suggested by the PDF_SEO_DISPOSABLE_LINK_FARM heuristic and the numerous unknown URLs, which is a typical precursor to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

Heuristics 6

  • 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.
  • 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://ad.ditroinfotech.com/laportal/ckeditor-ckfinder-integration/uploads/files/7576424048.pdf In PDF document text
    • https://dispecom.com/cms_dispecom/sgi_userfiles/userfiles/files/panazosajakexirobanejo.pdfIn PDF document text
    • http://keralastatetailorsassociation.com/userfiles/file/xajuv.pdfIn PDF document text
    • https://anmoul.com/userfiles/file/45100716996.pdfIn PDF document text
    • http://nguyenphat.com/public/default/ckeditor/files/musofagivuzimibovitame.pdfIn PDF document text
    • http://kiavysocina.cz/UserFiles/File/61645780358.pdfIn PDF document text
    • http://inkjetartandimage.com/Uploads/file/lokimugofeti.pdfIn PDF document text
    • http://gokea.org/upload/editor/files/5324385420.pdfIn PDF document text
    • http://yztools.com/images/upload/File/9504013886.pdfIn PDF document text
    • https://chulintemple.org/CKEdit/upload/files/69379538501.pdfIn PDF document text
    • http://anchor-m.com/js/upload/files/31387408331.pdfIn PDF document text
    • http://kowel.com/ckfinder/userfiles/files/1632563042.pdfIn PDF document text
    • http://maiodi.com/userfiles/files/92541195025.pdfIn PDF document text
    • http://romovi.net/sgi_userfiles/userfiles/files/denajudu.pdfIn PDF document text
    • http://www.siposferenc.hu/html/wokalufajubiwoxub.pdfIn PDF document text
    • http://machi-tomo.xyz/js/ckfinder/userfiles/files/vikekafusik.pdfIn PDF document text
    • http://gat-asset.com/CKEdit/upload/files/53459812009.pdfIn PDF document text
    • https://vannordenvastgoed.nl/userfiles/file/29016278418.pdfIn PDF document text
    • http://dayou.tw/uploadpic/files/202109180220162903.pdfIn PDF document text
    • http://vom-ragnaroek.de/uploads/file/13490341016.pdfIn PDF document text
    • http://teamtrinity.net/trinitya/file/wugenopatexor.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=pokemon+xy+zip+file+download+for+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_off0000ba04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA04 17608 bytes
SHA-256: 6fa952d481a71a207e76892bd387ea3d172966bd860dbce4f13565126451d988
font_01_sfnt_off0000e750.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE750 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ff67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF67 10848 bytes
SHA-256: 7456bea4a3be0675b3ae9c578b3723e9681c2db0897784752f62ddc00d8dacab