Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6b1e3d7a4e9041a…

MALICIOUS

PDF

94.2 KB Created: 2021-06-20 03:43:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: 461b5b8ba629f39d126b6667ad08b05a SHA-1: 478964edee0021e68604c47caf96685b8076a2c2 SHA-256: a6b1e3d7a4e9041aaa745450a37f69ac4d757db7bfb21e85f6af56440b3af17f
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.007 JavaScript

The PDF contains multiple links to external sites, some of which are hosted on compromised CMS platforms, suggesting a link farm designed to redirect users to malicious content. The heuristic 'SE_REMOTE_SUPPORT_LURE' indicates the document likely instructs the user to install a remote support tool, a common tactic for social engineering attacks. ClamAV detection further confirms its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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
  • Remote-support tool lure high SE_REMOTE_SUPPORT_LURE
    Document instructs the user to install, open, or connect with a remote-support tool such as AnyDesk, TeamViewer, Quick Assist, or ScreenConnect — high-risk in an unsolicited document
  • 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://educhina.mn/editor/files/gedatiguxubizezavizifabiv.pdf In PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a49593b0ded---gigosutobemirosanuz.pdfIn PDF document text
    • https://hasekei.jp/userfiles/file/xaminita.pdfIn PDF document text
    • https://www.westcountrystoves.co.uk/wp-content/plugins/super-forms/uploads/php/files/a2d80208f7175f7e57ecaa3c3dee9bdc/82779863931.pdfIn PDF document text
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/3943d5062664802510a48b3562d4fb27/rovajejonepebaxil.pdfIn PDF document text
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/160815b096ccd8---65693102270.pdfIn PDF document text
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a0ac16831e0---xemimibegeropexu.pdfIn PDF document text
    • http://www.tobywells.org/media/fckdir/file/malejugiti.pdfIn PDF document text
    • https://syntellect.ru/Repository/file/50523478492.pdfIn PDF document text
    • http://interel-rus.ru/test/sites/default/files/file/jixavezasefuwu.pdfIn PDF document text
    • https://ilmercatinosottocasa.com/file/46153254112.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160823d588e365---wozatiz.pdfIn PDF document text
    • https://catbasailing.com/upload/fck/file/81296718601.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=ni+circuit+design+suite+14.2+downloadPDF 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
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off000128aa.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x128AA 30176 bytes
SHA-256: 1e4c0785de47770f3c77b68a53e1688d68d4bb29ce56c1f0c1a4ca8667d1b92c
font_00_sfnt_off0000e706.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE706 5352 bytes
SHA-256: 2b509ec2eb30f2b4f76e262c7da347865e1c9bc60570a92538e2c181f6c53fb9
font_01_sfnt_off0000f969.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF969 21276 bytes
SHA-256: 66997847a2854ff1de85998e5e76a2127389eff0be71eecafbfd28757922aabc
font_03_sfnt_off00015d76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15D76 4324 bytes
SHA-256: ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3