Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb10e891624945c1…

MALICIOUS

PDF

83.9 KB Created: 2021-09-20 09:10:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 8866fdc349d6116c0ce72edc892e2a55 SHA-1: 0dbf0ff4243a00c109bf6222edbececaf0ff18f6 SHA-256: cb10e891624945c1fd5c128bda9de6c07352c8b9b322af33a4af738c085f7482
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains embedded JavaScript and numerous external links, many pointing to compromised CMS uploads or disposable hosting, suggesting a phishing or malware distribution scheme. The presence of JavaScript indicates an attempt to execute code within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 https://nomylo.ru/uplcv?utm_term=como+configurar+correo+de+hotmail+en+android PDF link annotation
    • https://vildmarksjagt.dk/userfiles/file/24424419119.pdfIn PDF document text
    • https://inprovitpuertorico.com/ckfinder/userfiles/files/41285785563.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/b2l1vtc71v4o7aj5mdbgkokh55/vewalirako.pdfIn PDF document text
    • https://parc-hotel.info/file/50690159055.pdfIn PDF document text
    • https://grouptm2.com/contents/files/23453778955.pdfIn PDF document text
    • https://flexi-cms.com/uploads/file/13614846520.pdfIn PDF document text
    • http://morethancars.nl/uploads/edytor/file/rabemofuxikejipaxuvobif.pdfIn PDF document text
    • http://sm300159.agchost.com/userfiles/files/79689849931.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/4e6468d85ad9c3b4fc173d968bf5b9bb/49420949397.pdfIn PDF document text
    • http://chunmianxian.com/upfolder/e/files/20210912162626.pdfIn PDF document text
    • https://corumosmanlimakina.com/js/ckfinder/userfiles/files/9251642799.pdfIn PDF document text
    • http://stroyvodservice.ru/upload/File/59305135323.pdfIn PDF document text
    • http://uralcomservis.ru/crn_fls/crn_files/lojinogopujagewo.pdfIn PDF document text
    • http://bdsps.org/slbdavbatala/userfiles/file/39278791312.pdfIn PDF document text
    • http://upasamed.org/Content/uploads/files/demeg.pdfIn PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/8cb4a0fb00188f0d74317ca4f8c93b52/zuxoziporunedetugij.pdfIn PDF document text
    • http://em-mould.com/ckfinder/userfiles/files/donegoxa.pdfIn PDF document text
    • http://solentpodiatry.com/jackvl940/web/content/images_uploaded/file/kunikuxopune.pdfIn PDF document text
    • http://manhchenang.vn/webroot/img/files/xaduworagodazirun.pdfIn PDF document text
    • https://marbeyoyun.com/calisma2/files/uploads/jegabogon.pdfIn PDF document text
    • https://hkfew.org.hk/ckfinder/userfiles/files/farezurijabuv.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_off0000de96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE96 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f6ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6AD 10888 bytes
SHA-256: 74971f68d393b14d9c7d90c7963103bfcb27a948d040ee1e849b35da92dd8c62
font_02_sfnt_off00010f6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F6C 19468 bytes
SHA-256: fdf9d763ca47f3d75dfe36a20b0f0ce28d83be526676e9b10dd61256638026a1