Malicious PDF — malware analysis report

Static analysis result for SHA-256 1f870a9fc94e54c5…

MALICIOUS

PDF

74.4 KB Created: 2021-09-04 10:24:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: ceee0f9383d06f6e3fb0aeaa30bf9a93 SHA-1: 9cad56fa06d92951591eb1dff1f5c52130bd5faa SHA-256: 1f870a9fc94e54c560dfdf84576fc2a413d5c1cf0d4f10728fbf903545150017
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many hosted on compromised CMS platforms or disposable domains, suggesting a link farm used for phishing or malware distribution. The presence of PDF-specific heuristics like 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this. No scripts were extracted, but the overall structure points to a malicious PDF designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://krisoc.ru/uplcv?utm_term=effective+questioning+strategies+in+the+classroom+pdf PDF link annotation
    • http://sip7.online/wp-content/plugins/super-forms/uploads/php/files/37fd900462637e23f39fab53bf329280/bibawadiwuduwipigew.pdfIn PDF document text
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c6cbb8bf3cd---namusamazum.pdfIn PDF document text
    • https://floridainvestment.cz/files/file/4523455069.pdfIn PDF document text
    • http://contrast.no/ckfinder/userfiles/files/64058823454.pdfIn PDF document text
    • http://alemotta.com/resources/original/file/79037723292.pdfIn PDF document text
    • http://midlandhigh65.com/clients/6/68/682e31fde28f8c6bff7ebba57332ef5f/File/xuvotifolomigagisojaku.pdfIn PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/29k8bih178rs2b2jsslc7523f0/55039798095.pdfIn PDF document text
    • https://avgdesign.com/userfiles/file/fafape.pdfIn PDF document text
    • http://www.smwiarus.pl/ckfinder/userfiles/files/41913435476.pdfIn PDF document text
    • http://lawngo.net/fckfiles/45516754619.pdfIn PDF document text
    • http://rocb-ap.org/file_media/file_image/file/dirurajamomokaduruwazek.pdfIn PDF document text
    • http://www.argentum.com/wp-content/plugins/super-forms/uploads/php/files/q82aje8m6kg9vpstacqc00adds/lidupidulosepo.pdfIn PDF document text
    • https://weblative.com/wp-content/plugins/super-forms/uploads/php/files/a89q5tnnd05g8cqc6vu2o8oasu/69925654560.pdfIn PDF document text
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/4fe6c31a76515c4443972666aae6b2d3/36241115128.pdfIn PDF document text
    • http://solamsys.com/userData/board/file/75705819619.pdfIn PDF document text
    • http://aihyang.com/userfiles/file/sarufaso.pdfIn PDF document text
    • https://thegioidongphuc.net/ckfinder/userfiles/files/kovumubupapad.pdfIn PDF document text
    • http://www.communityheroesproject.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a318f519d7e---83997722718.pdfIn PDF document text
    • http://klinikoral.com/img/userfiles/files/7752388027.pdfIn PDF document text
    • http://mirandatutoringcentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160728d57047f8---2924973464.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ec16e8ca65---56049303469.pdfIn PDF document text
    • https://lanjutpt1.com/contents//files/3391362207.pdfIn PDF document text
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/b72c6c595f187b89598f7c44192fb18d/jovosagalodedezeno.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_off0000be8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE8D 16748 bytes
SHA-256: 290e4e8be38cc60d226e42e1fb861b6cb438a5a2af1f6fda2831591e18b563f6
font_01_sfnt_off0000e95d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE95D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010174.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10174 11364 bytes
SHA-256: 845774ae6da8bca648526d75ec75855d45d667afeaa87ed83ee4338948380179

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