Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4084c0ed9757516…

MALICIOUS

PDF

81.8 KB Created: 2021-09-11 02:13:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a3d6aa2a79c8f77bc7aafaa911e424e4 SHA-1: 390d195a79b9ab3ab76062160166153a1b192b14 SHA-256: a4084c0ed9757516706b868cb7343222af44c726e153d0a207bc80e473d3b8a6
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, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be part of link farms or hosted on compromised CMS uploads. This suggests the document is designed to lure users to external sites, potentially for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://smidgel.ru/uplcv?utm_term=office+apps+for+android PDF link annotation
    • http://spc1991.com/ckfinder/userfiles/files/62729883844.pdfIn PDF document text
    • https://hamayeshniroo.com/shop/file/pokagove.pdfIn PDF document text
    • http://shuimotongyuan.com/userfiles/file/56862515271.pdfIn PDF document text
    • https://koltoztetes-szallitas-lomtalanitas.excore.hu/ckfinder/userfiles/files/62230623098.pdfIn PDF document text
    • https://www.eecpowerindia.com/codelibrary/ckeditor/ckfinder/userfiles/files/gawafujurebewut.pdfIn PDF document text
    • http://tonyprins.nl/images/uploads/file/nixagipadidobejetuzot.pdfIn PDF document text
    • https://hurghadalife.net/userfiles/files/28912144993.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/161353c6118189---88269254975.pdfIn PDF document text
    • http://phamtrangia.site/upload/files/60535666813.pdfIn PDF document text
    • http://fibertechnique.com/tmp/file/vipurozebo.pdfIn PDF document text
    • https://pro-biomed.com/admin/userfiles/file/77101766325.pdfIn PDF document text
    • https://auf.vn/wp-content/plugins/super-forms/uploads/php/files/537b5koq0r011b37ckvuijbar7/vabapov.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161394d7ec5980---rixujif.pdfIn PDF document text
    • http://sonhanint.com/uploadpic/sun/files/202108312221594045.pdfIn PDF document text
    • http://achwvs.love-mrt.com/upload/files/29054153324.pdfIn PDF document text
    • http://capesociety.ca/uploads/files/12673892841.pdfIn PDF document text
    • http://mofrantech.com/userfiles/file/46910635438.pdfIn PDF document text
    • http://gaestehaus-am-erlkoenig.de/img/editor/file/37545308956.pdfIn PDF document text
    • https://imapcb.org/wp-content/plugins/super-forms/uploads/php/files/f9dd9a27fb274d1beda591230859b64a/mumukogul.pdfIn PDF document text
    • https://gionggiacam.com/ckfinder/userfiles/files/58217397567.pdfIn PDF document text
    • https://jaukiaplinka.lt/ckfinder/userfiles/files/gepiru.pdfIn PDF document text
    • http://chonburi33.com/userfiles/file/gufarutarasuka.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_off0000dd8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD8E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f5a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5A0 17088 bytes
SHA-256: 14ade5e7096edd81fbb00060942e2507da96fb18e174971860740fcd92154063
font_02_sfnt_off000121d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121D6 10496 bytes
SHA-256: 665bbfd26aa153f8723616e6dbfc36990ba765e7ac8512fa5449aa7ec9c95d57