Malicious PDF — malware analysis report

Static analysis result for SHA-256 b728a4f351498c49…

MALICIOUS

PDF

81.9 KB Created: 2021-09-06 14:54:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: e1df4ed7683a730e800de3535a7b240b SHA-1: 84822a9d3877c8567c5361f49c76d784ef42c32b SHA-256: b728a4f351498c494aa71e6461d1b5c5e6a76d1ec31b89b478973b72be529d15
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable domains, indicating a link farm designed to lure users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://yds-wcv.jp/free_images/files/xamoduxebanetiserebejipi.pdf In PDF document text
    • http://www.darvidproperty.com/news/file/75828207527.pdfIn PDF document text
    • http://webmba.fr/client/logo/file/nizop.pdfIn PDF document text
    • https://angkortaxiservice.com/userfiles/file/2581071677.pdfIn PDF document text
    • http://www.peopleoftheheath.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c5f1fd560c---sowerimebogawu.pdfIn PDF document text
    • https://cupanghitam.com/contents//files/8998342766.pdfIn PDF document text
    • https://roweryelectra.eu/app/webroot/uploads/file/16236992456781.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608a2070d52d2---toduwaforivubuwuditenidi.pdfIn PDF document text
    • https://cribpointonline.org/cribpointonline/userimages/file/64015968470.pdfIn PDF document text
    • http://middlegeorgiacoinclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/160810fc31fae8---57765643821.pdfIn PDF document text
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/fd3f25461e1d14187163419ef13b362d/vawarajigasolewa.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d3a5401d04f---18912111548.pdfIn PDF document text
    • http://usatovl.ru/upload/fckeditorfile/36129666188.pdfIn PDF document text
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/611ecd1e934e0fa82eac219fb687c9cd/35192198936.pdfIn PDF document text
    • https://zzhqhi.com/d/files/wotumepitor.pdfIn PDF document text
    • http://dolphinegypt.net/userfiles/file/14192272918.pdfIn PDF document text
    • https://www.la-providence-ehpad.fr/ckfinder/userfiles/files/ludodiwopal.pdfIn PDF document text
    • http://www.corazondelsol.es/ckfinder/userfiles/files/desixopaxerunefelas.pdfIn PDF document text
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/81e8ef404bbc8d31f3844714c4b386f6/26466066997.pdfIn PDF document text
    • http://cke.hk/userfiles/2228676223.pdfIn PDF document text
    • http://www.gyndoktors.de/ckfinder/userfiles/files/rozurelutozitekoxutulu.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609689abb4e30---52404348700.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=schleswig+holstein+ferien+2020+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_off0000d96c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD96C 11140 bytes
SHA-256: 785c5c2074a3aeae0fdfea3f88404ba6a752b7424919ea9ee4b7a4fc3c3cb1a1
font_01_sfnt_off0000f340.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF340 18764 bytes
SHA-256: 4b2eaff7b06119b6d4ce88a794ad81620395fe555b51ef7e054e9cd482e2d11b
font_02_sfnt_off0001226c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1226C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1