Malicious PDF — malware analysis report

Static analysis result for SHA-256 e593d6dbc62bc4a5…

MALICIOUS

PDF

87.5 KB Created: 2021-07-05 21:00:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0a0b3e91b112f87554a7d2e3a60d387a SHA-1: 09f5857f3762d55053e06b3bb69d4008792cdbe2 SHA-256: e593d6dbc62bc4a564f0843d4f7c22549c62b461795da013efc38855bf7aee48
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users to malicious sites. The ML classifier strongly flagged this PDF as malicious, supporting the conclusion that it is used for phishing or malware distribution. No scripts were extracted, and the document body was unreadable, but the heuristic firings and extensive URL list are sufficient evidence.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

Heuristics 5

  • 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://krisoc.ru/uplcv?utm_term=compare+2+pdf+files+side+by+side
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/241c60a3kokad7oo3eo5nanj0f/sawatifojafarasogak.pdf
    • https://xn--bren-mgenwil-gcbf.ch/sites/default/files/fck-uploads/file/pesomitinewoxel.pdf
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5daf35d775---23457141231.pdf
    • http://lurome7071.com/clients/e/ec/ec9741bbacd2a64db66b94b03f3cd24d/File/1957521782.pdf
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cfdcccee51---metaxidapefagiwased.pdf
    • http://thepnguyentran.vn/media/ftp/file/16618473021.pdf
    • https://graffitipaintstudio.com/wp-content/plugins/super-forms/uploads/php/files/baad7a40f8753e005ad5cad43b4116c4/fojisitof.pdf
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096b9c1a551b---televodosesujet.pdf
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a86859db1d3---23633267342.pdf
    • http://anhbanglaw.com/userfiles/file/74147535375.pdf
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/845ec0f3289f929a9b11ee6bee51029f/18272473050.pdf
    • http://aweibel.com/Photo/file/17893742900.pdf
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/4ln0f5m5sg87cho7142o9j8uf6/sakugalo.pdf
    • http://beachfirebrands.com/userfiles/file/voxivabome.pdf
    • http://mikailang.net/userfiles/file/20210509094135_767621936.pdf
    • http://kosmonautika.ee/ckfinder/userfiles/files/45136863008.pdf
    • http://stihoplet.by/upload/editor/files/tudimowofotesajerubumufa.pdf
    • http://derma-dts.de/files/file/nojitibutotonikebakov.pdf
    • http://thehawthornnyc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b7131bf548---66257185163.pdf
    • http://inspiredindianfoundation.org/uploads/99933158780.pdf
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/jtolph9h5rvvs2bshg1veami04/66141722063.pdf
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072bc644743f---rinekepalukiraju.pdf
    • http://bakkervoorwinde.nl/app/webroot/files/ckeditor_files/files/kotutowimivexiko.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f375.bin
2f8590c43088ee009b15d48106a00cfe99444032e9aaf5425c586bf8608bb450
pdf-font-stream PDF embedded font (sfnt) at offset 0xF375 10860 bytes
font_01_sfnt_off00010c63.bin
4510a736a3da4088be3f3c91a3625f72faf6ca0fd6544395e842eced78cdb68d
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C63 17040 bytes
font_02_sfnt_off000138db.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x138DB 16792 bytes