Malicious PDF — malware analysis report

Static analysis result for SHA-256 d038c6999392c3b4…

MALICIOUS

PDF

70.5 KB Created: 2021-09-08 21:56:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-17
MD5: 311b96b0b53add5cb68c050e84468426 SHA-1: 1686b1e8e38131ad89b2b4d46401615b0bb6268e SHA-256: d038c6999392c3b4f016cf6ebec30a6f909b912cafac095cbd4f3ae22f4c5a97
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF document was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains embedded JavaScript and a large number of external URIs, many of which point to potentially malicious domains. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a tactic of using numerous links on disposable hosting to obscure the true malicious intent. The embedded JavaScript likely facilitates the redirection to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://zs-g.jp/app/webroot/js/ckfinder/userfiles/files/simajujunotezatutikidiki.pdf In PDF document text
    • http://kamkmori.cz/ckfinder/userfiles/files/sunuzogefabivupufu.pdfIn PDF document text
    • http://bangkokmagnetwire.com/ecodev_test/image_system/files/matimibotobak.pdfIn PDF document text
    • https://777mto.com/contents/files/xowoju.pdfIn PDF document text
    • http://msci.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/1613668ae2c356---33192841406.pdfIn PDF document text
    • http://i-p-p-c.com/ckfinder/userfiles/files/68888345424.pdfIn PDF document text
    • http://sinsg.com/files/fckeditor/file/60987800112.pdfIn PDF document text
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/161327462e5e14---23880685235.pdfIn PDF document text
    • http://sowiik.pl/userfiles/file/80911027859.pdfIn PDF document text
    • http://newbusan.net/FileData/ckfinder/files/20210906_D4D39757F5A0ECCB.pdfIn PDF document text
    • http://elcampoeco.org/FCKeditor/file/94177456466.pdfIn PDF document text
    • http://art-ball.net/files/file/41721727142.pdfIn PDF document text
    • http://szsahsh.com/uploads/files/tutuxokaxowizuzuto.pdfIn PDF document text
    • https://pinyardim.com/calisma2/files/uploads/fizupura.pdfIn PDF document text
    • http://instant-image.net/UserFiles/Site/File/37807879895.pdfIn PDF document text
    • https://interstudy.net/userfiles/file/21657206195.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/difixatepobedakatusa.pdfIn PDF document text
    • https://skatrip.com/basefile/skatripcom/files/15943054156.pdfIn PDF document text
    • https://el-tall.pl/pics/file/zidoli.pdfIn PDF document text
    • http://ihanzao.com/userfiles/file/20210908155103_1418612866.pdfIn PDF document text
    • https://razredna-nastava.net/files/rifuwuzagopajobap.pdfIn PDF document text
    • https://loyallcanada.com/editor_files/file/nokonogosixa.pdfIn PDF document text
    • http://melly-incendie.fr/img_db/guwel.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=best+security+apps+for+android+2016PDF 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_off0000b1e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c9f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9F8 11296 bytes
SHA-256: 89f8486b6e9ab3f9b8558104f65f1a13468fb660e49318f9a6d13178d18ef45d
font_02_sfnt_off0000e4c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4C6 15920 bytes
SHA-256: c39c9afbfcff592cfcae1884835eff69dc596fd5add19ae0cdb3c2a169f320de