Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6c41237d6270a84…

MALICIOUS

PDF

74.9 KB Created: 2021-09-12 04:55:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 5585cba0cbc30eb10fa908fa2bc64ad6 SHA-1: db95991e2d4dacc3d5f7360990d7543d191a3736 SHA-256: a6c41237d6270a84414fdd9855f8b1c325856010fea1b8b8995b4e326cf2781e
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various PDF files, indicating a link farm or a distribution mechanism for further malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM specifically identifies the pattern of using disposable hosting for a large number of links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://tomas-music.com/contents/files/13478541008.pdf In PDF document text
    • https://behagi.eus/files/galeria/files/guremiwepusukunid.pdfIn PDF document text
    • https://adtw1.com/ckfinder/userfiles/files/dilubozasumusefatipeduka.pdfIn PDF document text
    • https://lbjgold.in/ckfinder/userfiles/files/58505743704.pdfIn PDF document text
    • https://rotitelor.com/contents/files/refolafubukoxagimizepurix.pdfIn PDF document text
    • https://healthmatters.me/userfiles/file/66022688753.pdfIn PDF document text
    • http://turinimoti.com/assets/userfiles/file/lemipakawot.pdfIn PDF document text
    • http://elektro-galerie-hamburg.de/userfiles/file/49813054006.pdfIn PDF document text
    • http://bienbao.org/uploads/files/zatigutifatij.pdfIn PDF document text
    • http://ydchem.cn/filespath/files/20210910075333.pdfIn PDF document text
    • http://contactfm.be/userfiles/files/libunaferofu.pdfIn PDF document text
    • http://inventory-acepipe.com/images/uploads/files/96576292167.pdfIn PDF document text
    • http://veterinariacasettamattei.it/userfiles/files/87356076355.pdfIn PDF document text
    • http://klusjesindex.nl/images/uploads/waramexozex.pdfIn PDF document text
    • https://pgp-puh.hr/fck_media/file/sewelafa.pdfIn PDF document text
    • https://iphone-odklep.si/vsebina/gemoponuxosifexofulagasu.pdfIn PDF document text
    • http://be-now.pl/userfiles/file/soliwutorawokak.pdfIn PDF document text
    • http://originalavto.ru/userfiles/file/12253438487.pdfIn PDF document text
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613d42a8899d4---67893268345.pdfIn PDF document text
    • http://01host.ru/userfiles/files/samuvudajo.pdfIn PDF document text
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/d0a949945e2b2bb596dfb386008ba3c0/furamujasonejovuk.pdfIn PDF document text
    • https://pemaboutiquehotel.com/assets/userfiles/files/8881867110.pdfIn PDF document text
    • http://mnogonomerov.ru/uploads/file/49573237367.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=ad+free+alarm+clock+appPDF 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_off0000c27f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC27F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000da96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA96 10392 bytes
SHA-256: 786ca21a768ec4c625470526335a592a3584bf00e30539bd752f3e6237d999b0
font_02_sfnt_off0000f21a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF21A 17104 bytes
SHA-256: e3e25a3bd6dbcc9bcf3c5ce40c02989afb414d9db5ee80c4bcc66ca0a068c858