Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4ac91c0e15f6725…

MALICIOUS

PDF

126.3 KB Created: 2021-08-06 19:11:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: fa0c6cdc97bf2940d080add6fdc2b295 SHA-1: a480e1608ad8e6bc755fbcb31e02a463565da56f SHA-256: a4ac91c0e15f6725222a1c4e3bd98b4e41f9c0b14c8b58f768d2a8673b44de14
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised CMS uploads and disposable hosting, suggesting it's designed to redirect users to malicious sites. The presence of numerous unknown URLs further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8114

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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
  • 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://kiuruvedenlukio.fi/tiedostot/file/86075324110.pdf In PDF document text
    • http://msiutilities.biz/documents/gawubiretan.pdfIn PDF document text
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/vbbo3smq0mjm3n6s77aqg8v0it/zidunegejugusozomo.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/texuzofuvulumisovafe.pdfIn PDF document text
    • http://doubletroubels.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d3dfe0d3ba---6513848691.pdfIn PDF document text
    • http://xn----7sbbbizu2bxaod.xn--p1ai/userfiles/file/tukomufedagemovukifusavuk.pdfIn PDF document text
    • http://auburn-companies.com/userfiles/files/zovanixoxat.pdfIn PDF document text
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/0295ac4b2d5dd04de76de20a2c65f4ae/63204482266.pdfIn PDF document text
    • http://cameradungphat.com/uploads/files/9808995632.pdfIn PDF document text
    • http://xn--72c7caerxx0d3a9eve.com/UserFiles/File/16673205983.pdfIn PDF document text
    • https://jetzterstrecht.hamburg/wp-content/plugins/super-forms/uploads/php/files/ef7r4qq83ld7umj4rdv8q8atp9/giwozesozakemutodub.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609d30206b44d---tebudanudefa.pdfIn PDF document text
    • http://mu-rrrc.com/userfiles/file/82546720225.pdfIn PDF document text
    • http://sriagasthiyarastro.com/FCKeditor/userfiles/file/silax.pdfIn PDF document text
    • http://fmi.lu/userfiles/files/jemabaguxokekab.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/160aaa3a857603---95444344002.pdfIn PDF document text
    • https://www.americansummercamps.com/wp-content/plugins/formcraft/file-upload/server/content/files/160792686c5d6a---taxavaxikelapoweg.pdfIn PDF document text
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/27340ea0319fe7a5a8da462601ae17bc/69349416284.pdfIn PDF document text
    • https://krantiservice.com/ckfinder/userfiles/files/verunosa.pdfIn PDF document text
    • https://fairtradeportal.pl/userfiles/file/11977521214.pdfIn PDF document text
    • https://trimix.bg/UserFiles/File/49124087811.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/51f0acf49eaea8612fb480bc45588f9e/jifetaxidijegode.pdfIn PDF document text
    • http://perles-del-beya.com/userfiles/file/napaw.pdfIn PDF document text
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/1c69e554a5bcebd5ec9baf0e1392e29f/kisov.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a605f1d8d70---buvunavez.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=what+are+the+disadvantages+of+quota+samplingPDF link annotation
    • 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_off0001994e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1994E 18132 bytes
SHA-256: f0b057f3282647f83d525a95b33b80ade588a557dd1c44b74d60b083638de557
font_01_sfnt_off0001c930.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C930 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001e147.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1E147 11248 bytes
SHA-256: 77619303144d8889b6e15bfcdfe5167a48eeee06a6e8ec08ae6f4436fcf6ee0b