Malicious PDF — malware analysis report

Static analysis result for SHA-256 bbbdb721bced60f9…

MALICIOUS

PDF

78.0 KB Created: 2021-09-23 19:04:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 4f4b2e15bf70f0564b55d5895ffa247e SHA-1: 9fcba4fbb3f400608ddf7724d2088b019e72239b SHA-256: bbbdb721bced60f956f52140bd7b37905095a00a5e6d348d5975d10a87d09af3
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, and exhibits characteristics of a link farm pointing to compromised websites. Several heuristics indicate the PDF is designed to host external links, with some pointing to compromised CMS uploads and others to disposable hosting, suggesting an attempt to redirect users to malicious content. The presence of numerous unknown URLs further supports this.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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
  • 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.
  • 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://tessuno.com/upload/files/6145ce8b8cebf.pdf In PDF document text
    • http://a-mega.ua/images/uploads/file/49323467869.pdfIn PDF document text
    • https://vestol.bg/files/file/zemopawololono.pdfIn PDF document text
    • https://mayphotocopydogia.com/upload/files/22832171349.pdfIn PDF document text
    • http://gemculture.com/userfiles/file/jafisuwezapimevibez.pdfIn PDF document text
    • http://hainescentreasia.com/images/file/90578780158.pdfIn PDF document text
    • https://kingdomofgodmn.org/userfiles/files/xepiz.pdfIn PDF document text
    • http://lambanghieuquangcaogiare.net/vietkiendo/upload/file/jamegubi.pdfIn PDF document text
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/003237f41ee9485f6d2cb3a88d893b24/muvapot.pdfIn PDF document text
    • http://zovsh.com/Uploadfiles/files/juzigegupamazoke.pdfIn PDF document text
    • http://capital96.com/userfiles/file/lewevamedalopifuluwu.pdfIn PDF document text
    • http://lapmaymn.samdigroup.vn/app/webroot/upload/files/16494160180.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613266e148d83---41061808269.pdfIn PDF document text
    • https://inijariku.com/ckfinder/userfiles/files/11608079130.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614c7ee9a79ae---xevasodonidof.pdfIn PDF document text
    • http://mdsalon.ru/img/lib/file/70677877826.pdfIn PDF document text
    • http://hotelrealerimini.it/userfiles/files/82370627193.pdfIn PDF document text
    • http://www.dr.schure.net/ckfinder/userfiles/files/73406458875.pdfIn PDF document text
    • http://chemicalengineers.ie/images/17331828820.pdfIn PDF document text
    • http://a-pluset.com/userfiles/90493243759.pdfIn PDF document text
    • http://camel-republic.com/media/userfiles/files/wipokijivixivajuguke.pdfIn PDF document text
    • http://orthopediedelft.eu/files/34241882099.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=reboot+option+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_off0000cd81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD81 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e593.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE593 17600 bytes
SHA-256: b4c0cc035154013ce88d19747c039c1b58cfc1024c91755efd4cf5f43abb72b9
font_02_sfnt_off00011347.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11347 10356 bytes
SHA-256: a6e0282ab25ad4454951afc27dcfdf98d72b54312648bf9c2b8ff459c991ccb4