Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1fd1e0b6140e877…

MALICIOUS

PDF

92.5 KB Created: 2021-09-06 22:18:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: b1aa092a981d03ab13cf05c856a93281 SHA-1: 40fa73d48dc76481e9031cb43361d70e7d67e7bc SHA-256: a1fd1e0b6140e87749f857abb20bab0bd159a03f020de9a7d2acdf6a21d10edb
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier. It contains embedded JavaScript, which is likely used to redirect users to a series of links hosted on compromised websites, a common tactic for phishing or distributing further malware. The PDF also exhibits characteristics of a link farm, with numerous external URIs pointing to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://nakamurasangyou.jp/app/webroot/uploads/files/56526377604.pdf In PDF document text
    • http://sys-svinding.dk/userfiles/file/nomatososejukogejufajur.pdfIn PDF document text
    • http://se-ty.ru/uploads/userfiles/file/6703597842.pdfIn PDF document text
    • https://rocksoliddesigns.biz/userfiles/file/72459358168.pdfIn PDF document text
    • https://solarconsulting.org/wp-content/plugins/super-forms/uploads/php/files/868f0ec1c2e11a80437305a13765d1ab/veveretasejuwapifasufugu.pdfIn PDF document text
    • http://djpress.pl/Image/files/vuketugabalusikise.pdfIn PDF document text
    • http://tuhocxuatnhapkhau.com/uploads/ckfinder/files/23560079719.pdfIn PDF document text
    • http://daieimotors.com/js/upload/files/jerumagabaneme.pdfIn PDF document text
    • http://csc0311.com/userfiles/file/20210825191031_ljo84d.pdfIn PDF document text
    • https://studio-september.com/wp-content/plugins/super-forms/uploads/php/files/4cc6484cacbda7cd5b0391863613a229/wujos.pdfIn PDF document text
    • https://lea-inc.com/wp-content/plugins/super-forms/uploads/php/files/d4004795176d13fa88d602f110ef3c51/vexan.pdfIn PDF document text
    • http://nitexprofi.cz/userfiles/file/zoxakomabiludovojapi.pdfIn PDF document text
    • http://sibleyestateplanning.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/todozewixupavugema.pdfIn PDF document text
    • http://nirmalapublicschoolerumely.com/userfiles/file/7114634408.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/16081115290e3b---78741390550.pdfIn PDF document text
    • http://kapelski.pl/userfiles/file/33146421531.pdfIn PDF document text
    • http://asfalon.com/__files/file/66026889903.pdfIn PDF document text
    • http://nusratali.com/userfiles/files/70210844572.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161324482ed11c---41327725181.pdfIn PDF document text
    • http://mega.kz/media/upload/files/tigan.pdfIn PDF document text
    • https://thaihoanghung.com/upload/files/60748503507.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/16077f55e4acb3---96307515333.pdfIn PDF document text
    • http://x-mobio.com/upload/files/bakefejalubomamabu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=social+cohesion+and+religion+pdfPDF 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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010243.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10243 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011a55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A55 19068 bytes
SHA-256: 40223fd7447a05f89eb222caea4a02fff2070a4f84760f84e5e74abd8f04d887
font_02_sfnt_off00014bcc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14BCC 10876 bytes
SHA-256: 6c23787ec66d5f72c10eed59630135fd763c7969f9e2b93224ab451d668183f4

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