Malicious PDF — malware analysis report

Static analysis result for SHA-256 23a701b8576ae242…

MALICIOUS

PDF

98.6 KB Created: 2021-09-17 11:44:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5b976600b35d2ca69128d8e5e53d9f65 SHA-1: e7193888dcb258db8dedf5c3cd1ea72a3590484e SHA-256: 23a701b8576ae24288e7eb383257f99d956ab54a30b48f635d3de51ef2771798
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of embedded JavaScript indicates potential for further malicious actions, such as downloading additional payloads or executing exploits.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9862

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://crysiq.ru/uplcv?utm_term=scribble+app+apk
    • http://giadinhlaurenso.org/upload/files/59502141254.pdf
    • http://xsteelstock.com/d/files/9425517877.pdf
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/82e4cd19d5f01a291a8e1a117f257fb4/48830536914.pdf
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138a6a95dfda---6716607396.pdf
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613e07a0a0afb---nufitutoxe.pdf
    • http://aluminial.pnh.pt/js/ckfinder/userfiles/files/zijuvasodoberasij.pdf
    • http://kvrhousing.com/uploads/39209459572.pdf
    • https://funbugs.ie/files/file/84834865385.pdf
    • http://think6.net/ckfinder/userfiles/files/20210914092517.pdf
    • http://luxcottage.ru/stroykamen/userfiles/files/ziparapal.pdf
    • https://houstoncoinclub.org/FCKeditor/file/91574004134.pdf
    • http://tks-forever.com/upload/2021/09/15/file/34255511346.pdf
    • http://polaryachts.com/res/wysiwyg/file/55071195260.pdf
    • https://chiataiec.com/userfiles/Proj_Name/files/tivetomasaloforisoravowa.pdf
    • http://theurbanbazzaar.com/userfiles/file/93893842477.pdf
    • http://thoitrangvabaoho.com/Images_upload/files/navuminumadonumajatutif.pdf
    • https://buzascsaba.hu/userFiles/file/todovigaw.pdf
    • http://www.kickcommerce.com/userfiles/file/wajix.pdf
    • https://specialgarden.ro/userfiles/file/niselagumepul.pdf
    • https://allmassage.net/upload/file/20210903101805.pdf
    • http://taiwanglassgroup.cn/userfiles/file/rixemuraguz.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ec70.bin
9492e28a8f533086419d16b9ab0bddd1e3220a75ec29f28a1be06239a5547799
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC70 26776 bytes
font_01_sfnt_off00012eef.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12EEF 16792 bytes
font_02_sfnt_off000146fc.bin
9d2bb2d94384256bb38bab4c3005c13f44a8b25eb5b232dcefe64ad24aae4b51
pdf-font-stream PDF embedded font (sfnt) at offset 0x146FC 1868 bytes
font_03_sfnt_off00014fb4.bin
570246e6c96584ca45c07ab07356ffdaca6649f6459e8f87d92624153cbcf35d
pdf-font-stream PDF embedded font (sfnt) at offset 0x14FB4 10184 bytes
font_04_sfnt_off0001665b.bin
fddcbe21bdf9fb2753729b4ab5b26d7a3fbb01e3fe51d41ab0725360e25c189d
pdf-font-stream PDF embedded font (sfnt) at offset 0x1665B 16244 bytes