Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc7a57568c6890d2…

MALICIOUS

PDF

77.9 KB Created: 2021-09-21 00:12:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: c0c9b78ef4784c16c72a2264831ed680 SHA-1: 1b460fd999a8f7c61c6906f1769f9bf25d043caf SHA-256: dc7a57568c6890d29f371bc8a21e88bb8d0c8ace80cbafb445e7330daa112ca6
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to domains associated with compromised CMS uploads or disposable hosting, indicating a link farm designed to lure users to malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, and the document body was unreadable, but the heuristic findings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://garglob.ru/uplcv?utm_term=felder+chemical+engineering+pdf PDF link annotation
    • https://sk-elektron.ru/ckfinder/userfiles/files/66113936413.pdfIn PDF document text
    • http://ansatrans.ru/admin/ckfinder/userfiles/files/70207587547.pdfIn PDF document text
    • https://tmtteks.com/files/livojekuwodi.pdfIn PDF document text
    • http://cleannshieldflorida.com/wp-content/plugins/super-forms/uploads/php/files/78a94f18f545040d918110f86ad1c48e/bavobafuporuxi.pdfIn PDF document text
    • http://madinagirls.com/easydo%20v2.00/files/uploads/60980996181.pdfIn PDF document text
    • https://inprovitperu.com/ckfinder/userfiles/files/10888465207.pdfIn PDF document text
    • http://bibliotekaszamocin.pl/img/upload/files/liraf.pdfIn PDF document text
    • http://izmirtavla.com/upload/file/99340780961.pdfIn PDF document text
    • http://sattosushi.com/uploads/files/87129733386.pdfIn PDF document text
    • http://heyumpnd.com/userfiles/file///xopefaxasojilalo.pdfIn PDF document text
    • http://titusauto.hu/kepek/file/nawugimigevaxomibifeg.pdfIn PDF document text
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/d9pucqgqb7ph4dg4b7cd44ilp3/toxufafow.pdfIn PDF document text
    • https://postelezmasivu-zlin.cz/ckfinder/userfiles/files/divinivut.pdfIn PDF document text
    • https://mimpishiosatu.com/contents/files/79079175056.pdfIn PDF document text
    • http://letnipohar.cz/upload/file/67122642673.pdfIn PDF document text
    • http://hzkontejnery.cz/ckfinder/userfiles/files/68189168690.pdfIn PDF document text
    • https://hobbes-group.com/upload/files/4203053859.pdfIn PDF document text
    • http://silver1979.com/upload/file/56629327412.pdfIn PDF document text
    • http://saaretravel.ee/images/file/11899988717.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16143d1087d532---suginobemebawexabejew.pdfIn PDF document text
    • http://world-housing.jp/ckfinder/userfiles/files/kitudiwuseluvofejivaxabib.pdfIn PDF document text
    • http://domadoma.cz/userfiles/file/zufomapetalotepiwiwugi.pdfIn PDF document text
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1612fc1df53df2---6238575594.pdfIn PDF document text
    • https://xosobacninh.vn/webroot/img/files/xenudukiwaf.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_off0000ce85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE85 10660 bytes
SHA-256: ba2b9320c888fee32b0c3f5e9aab2cf3131977338eba5b512f9aa9b9dd6d2d8b
font_01_sfnt_off0000e65d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE65D 17020 bytes
SHA-256: 2ba8392bc208e7dba2f6ff9b14737dc6cb51df2de9efcaea32457cf98423f4cd
font_02_sfnt_off00011233.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11233 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1