Malicious PDF — malware analysis report

Static analysis result for SHA-256 73a6e39a043b899c…

MALICIOUS

PDF

85.8 KB Created: 2021-09-24 11:26:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: e3e57d1247aae463f5cb208b0c914770 SHA-1: d90ff329878134199ade4a3c5d944a6ba72b5cba SHA-256: 73a6e39a043b899c76c37b4c93f08de6bd0c2f514bc0b9289f74966122be9aa1
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains embedded JavaScript and a large number of external URIs, many of which point to disposable domains, indicating a link farm or redirection scheme. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically calls out this behavior. The embedded JavaScript likely facilitates the redirection or download of further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://freewest.at/kewuxivuze.pdf In PDF document text
    • http://forti.in/userfiles/file/bimowolefifamijugomenire.pdfIn PDF document text
    • http://assessmentinsight.com/ckfinder/userfiles/files/7301365614.pdfIn PDF document text
    • http://yyfxsw.com/upload/files/66918882002.pdfIn PDF document text
    • http://cafegreenwichvillage.com/uploads/files/gasetopuxoxozobibop.pdfIn PDF document text
    • https://felicityokolo.com/file/49917686351.pdfIn PDF document text
    • https://harkakotony.hu/UserFiles/file/doxalizezajowizibule.pdfIn PDF document text
    • http://sahamit.net/userfiles/file/jugokusomudagaroja.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140b3ee6fe3c---57393724724.pdfIn PDF document text
    • https://noble-program.site/js/ckfinder/userfiles/files/sukefoxegat.pdfIn PDF document text
    • https://topupdana.com/contents/files/9428571931.pdfIn PDF document text
    • http://karcannakliyat.com/userfiles/file/donobasika.pdfIn PDF document text
    • http://www.velkoobchod-man.eu/ckfinder/userfiles/files/80795697407.pdfIn PDF document text
    • https://ikuseikyokai.jp/ckmedia/files/54528193938.pdfIn PDF document text
    • http://www.hkrns.org.hk/ckfinder/userfiles/files/97513709757.pdfIn PDF document text
    • http://bikipvuikhoedep.com/app/webroot/files/editor_upload/files/xamukulowekabojuxu.pdfIn PDF document text
    • https://ezsprinting.com/userfiles/file/78771576197.pdfIn PDF document text
    • http://catherine-massage.com/ckfinder/userfiles/files/17827048024.pdfIn PDF document text
    • https://cingenito.ca/upload/editor/file/82590642638.pdfIn PDF document text
    • https://baoholaodong24.com/userfiles/file/37559422244.pdfIn PDF document text
    • http://uklearningnetwork.com/userfiles/file/tizonujaxinas.pdfIn PDF document text
    • http://prosefkuchare.cz/userfiles/67911203255.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/9ad8c9f8e7f9f60586d452f0fd2e7698/telunepabojuxag.pdfIn PDF document text
    • http://carzip.biz/files/uploads/files/fexufono.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=best+hdr+app+androidPDF link annotation
    • http://s250801404.onlinehome.fr/img/uploaded/file/67427021594.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_off0000ead5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAD5 10496 bytes
SHA-256: 863ee5b480f3b8a0cf0e381a5de21f2f2c07c14bee68569f9114d4a580df8464
font_01_sfnt_off000102a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102A5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011ab7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AB7 18056 bytes
SHA-256: a67410d2b76d0a6ac53dabe890c64f03c60d69e795e20d8df8731b2fcb588c5b