Malicious PDF — malware analysis report

Static analysis result for SHA-256 788f85efcd2f6315…

MALICIOUS

PDF

83.8 KB Created: 2021-09-14 01:58:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: d5bb5e853a5dfa27d8475ae5fe22b5f5 SHA-1: 0b65f851c6176d65d6ae2ea2763df2011e686db6 SHA-256: 788f85efcd2f631525198ecde3374852e7755c910135627a9a5529f8afa4f172
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as 'Pdf.Phishing.Trojan' and an ML classifier indicated a high probability of maliciousness. Static analysis revealed numerous embedded URLs, many pointing to compromised or disposable domains, characteristic of a link farm used for phishing or distributing further malware. The presence of multiple PDF link farm heuristics reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://sethhukumchandschool.com/userfiles/file/42023837559.pdf In PDF document text
    • http://boxerdapolenta.com/cmsimple/images/file/sanexivedekeponav.pdfIn PDF document text
    • http://zkmeiqi.com/admin/ckfinder/upfile/files/sageliwis.pdfIn PDF document text
    • http://cinstech-inspect-survey.com/fckeditor_userfiles/file/12041616507.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/6cca78ef11103e3628538efbe66f40d7/33096215537.pdfIn PDF document text
    • http://olech-rzeszow.pl/userfiles/file/544191364.pdfIn PDF document text
    • http://uchid.com/uploads/file/kabijewivenul.pdfIn PDF document text
    • http://protetyka-lublin.com/images/wyswig_images/file/vuwipumadokofobino.pdfIn PDF document text
    • http://cerrutistudio.eu/userfiles/files/58429359359.pdfIn PDF document text
    • https://zbmbudomont.pl/userfiles/file/15325291913.pdfIn PDF document text
    • http://www.startbatteries.gr/ckeditor/ckfinder/userfiles/files/21169394864.pdfIn PDF document text
    • https://evpersoneli.net/ev-personeli/file/66667001043.pdfIn PDF document text
    • http://cesishotel.com/res/wysiwyg/file/52721491788.pdfIn PDF document text
    • http://meetburgerusa.com/uploads/files/guzexozuz.pdfIn PDF document text
    • https://www.oasipizza.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613e25fc1af7c---12675738143.pdfIn PDF document text
    • http://zhxndl.com/uploadfiles/files/36988465574.pdfIn PDF document text
    • http://www.hkrns.org.hk/ckfinder/userfiles/files/dararonixinusipamosub.pdfIn PDF document text
    • http://vedepcuaem.com/luutru/files/zimumum.pdfIn PDF document text
    • http://ckrestaurantgroup.com/ckfinder/userfiles/files/85476844134.pdfIn PDF document text
    • https://absoluteanytime.com/media_file/files/files/fedusasogamipirakijebo.pdfIn PDF document text
    • https://travelinnsuites.com/nbloom/fckuploads/file/kesasupid.pdfIn PDF document text
    • https://nicklason.se/ckfinder/userfiles/files/gubuwimerun.pdfIn PDF document text
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/bdb0e3675392effcd0e6393b2d842a7b/74302996185.pdfIn PDF document text
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/669d4548f54b1a217a539873f00dc9c0/49035054002.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=record+android+emulator+screenPDF 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_off0000e362.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE362 10676 bytes
SHA-256: 99ce821fccc62411c8ab2bc535bd7db82d5fb285472ac714622e9624f590e075
font_01_sfnt_off0000fbda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBDA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000113ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113EC 17592 bytes
SHA-256: d5aa8f8aa237d42a712a62ae80d59bc4df01bd54885d0d3efc8ba1cfea87c3ac