Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf9bb43e73658561…

MALICIOUS

PDF

88.4 KB Created: 2021-07-16 18:36:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 444ccf04fac26f359ce9284ffc56a8d4 SHA-1: b94533e6773b55696601aea74e7498d7154da8d9 SHA-256: bf9bb43e736585617f5f67f072bf45456e924a014438535d382ac38e0d80989e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external links, many pointing to WordPress sites utilizing the 'super-forms' plugin, indicating a link farm designed to obscure malicious destinations. ClamAV detected this file as Pdf.Phishing.Trojan, and the ML classifier assigned a high probability of maliciousness. The presence of embedded JavaScript, though not directly analyzed for specific actions, is often used in such PDFs to facilitate redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://study-go.info/wp-content/plugins/super-forms/uploads/php/files/49b81e149a0a30cc42ac7b90c293b402/54581528031.pdf
    • https://www.citysecurity.org.uk/wp-content/plugins/super-forms/uploads/php/files/aankvhd2js3l14ms741simqm3v/28622888307.pdf
    • https://medgarlci.com/wp-content/plugins/super-forms/uploads/php/files/0772244da73b115c4d8bf816cecdcb6a/bomimubizub.pdf
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/f9ab0ldb07e6g1411vgdl69pak/5048696324.pdf
    • https://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/64711863ea0774b03bf2098a653b6d77/87455160786.pdf
    • https://daleplumbinginc.com/wp-content/plugins/super-forms/uploads/php/files/c89e7a5484fcd7f7fa0e14bf39409da7/16217907126.pdf
    • http://nova-auto.com/upload/mokajemalij.pdf
    • http://adabaskimerkezi.com/upload/file/8503426070.pdf
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6f8c5ec3ff---62149861195.pdf
    • https://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/9p251chmjoafgv0lo1mqi2ma9r/90727294555.pdf
    • http://www.mueblesgamez.com/ckfinder/userfiles/files/dader.pdf
    • https://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/8ab206aa0595b61ae103541091b31511/wejaku.pdf
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090fddda30a0---1809624883.pdf
    • http://4bzsoftware.com/Images_upload/files/musofelotodotokejaxo.pdf
    • https://dialogueinpraxis.net/files/docs/47465952532.pdf
    • https://uclerbaklava.com/resources/file/29830686515.pdf
    • http://shipagents.nl/uploadfiles/file/gofovixovuj.pdf
    • https://doctorchina168.com/upload/files/suduzavutamofis.pdf
    • https://www.skyline-recruiting.com/wp-content/plugins/super-forms/uploads/php/files/f93b309d1895007f436dc99367bee440/zupofedapolutaz.pdf
    • https://ajitcoatings.com/uploads/37279085825.pdf
    • http://samtekelektrik.com/files/netote.pdf
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc5764af1a---begusekoj.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=fifo+process+costing+method
    • 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_off0000f78d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF78D 16792 bytes
font_01_sfnt_off00010f9f.bin
dd8808da788ba5231f935b019cec97b0c9d4346687347c13a54b62bb697acb02
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F9F 16976 bytes
font_02_sfnt_off00013bc5.bin
bd58444536f57c581b22daa90f743ea2c0ae72968f803df8c4ede9ea3e937edc
pdf-font-stream PDF embedded font (sfnt) at offset 0x13BC5 10836 bytes