Malicious PDF — malware analysis report

Static analysis result for SHA-256 654a7ab9c9ebc436…

MALICIOUS

PDF

76.2 KB Created: 2021-09-01 12:52:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 87915171e27bc6f9553f34d2d13f0b05 SHA-1: fe0229f7d80b4ebe1c5e2643e7ea2d344d997577 SHA-256: 654a7ab9c9ebc436fc23ca1a97a84150abf3d93ae2ae517a461a6a4f5e8e8271
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised CMS upload directories or disposable hosting, suggesting it functions as a link farm. The presence of these links, combined with the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic, strongly indicates the document's purpose is to redirect users to potentially harmful websites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://coretry.ru/uplcv?utm_term=following+due+diligence PDF link annotation
    • http://chothuethietbi.info/img/files/72288436678.pdfIn PDF document text
    • http://omgmediatank.com/userfiles/files/pubugujavejelopewo.pdfIn PDF document text
    • https://imapcb.org/wp-content/plugins/super-forms/uploads/php/files/2m9bc0j29f38louqb4ka3dddd3/78414140959.pdfIn PDF document text
    • http://dianacb.cz/userfiles/file/55623661411.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b16a58bd29f---bobamusaf.pdfIn PDF document text
    • http://aleeblog.com/wp-content/plugins/super-forms/uploads/php/files/dsa60j16rag6pcuksgi0a747i3/39741174051.pdfIn PDF document text
    • http://vasset.bg/userfiles/file/nuwuvidawoforugirafugas.pdfIn PDF document text
    • http://chinazzjx.com/d/files/bazipefeluviguriv.pdfIn PDF document text
    • https://korzo-galeria.hu/files/file/57884005881.pdfIn PDF document text
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/a6674134ceef2c74cdc8c2ddbdc26a7b/mekiveji.pdfIn PDF document text
    • http://playbabydoll.com/userfiles/file/46107853521.pdfIn PDF document text
    • https://doctmcooper.com/userfiles/files/65693841063.pdfIn PDF document text
    • http://md-servicios.com/userfiles/file/wanujesofugeb.pdfIn PDF document text
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f0fd9ae5e6---30560986864.pdfIn PDF document text
    • http://bafiti.com/sklep/userfiles/file/ruxomabo.pdfIn PDF document text
    • http://wych123.com/upload/files/gopidewus.pdfIn PDF document text
    • https://leifs-auto.dk/images/file/37558262740.pdfIn PDF document text
    • http://pressvaluation.net/userfiles/file/gidukabizalumatitawex.pdfIn PDF document text
    • http://beloit1962.com/clients/8/83/8368a4f838dea3176655029ae9e337da/File/vuzuvanizixubexe.pdfIn PDF document text
    • https://gresathouse.com/wp-content/plugins/super-forms/uploads/php/files/8d8732280f8f1364e25170abf7c04f1f/puwuzufiled.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160718f64e2d18---30825422566.pdfIn PDF document text
    • https://trexanh.net/upload/files/709686594.pdfIn PDF document text
    • https://ferado.vn/userfiles/file/86751219529.pdfIn PDF document text
    • http://nepodoshlo.kz/ckfinder/userfiles/files/vaxerinuzavinavuwe.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_off0000c7ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7FF 17260 bytes
SHA-256: 0729fc7c421bad3134dd3984d3c1febbed14208d9a3e5fe52940733313b7304c
font_01_sfnt_off0000f3ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3CE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010be5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BE5 10180 bytes
SHA-256: 3c363bff372b10a3e6b72b2f7e243fcb5c29c40f7eff1e9d1b04ae5bd3431bdd