Malicious PDF — malware analysis report

Static analysis result for SHA-256 cba5377813b1169c…

MALICIOUS

PDF

89.0 KB Created: 2021-08-13 12:56:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 65cc8987797ba9e8e0b895bbae8fa143 SHA-1: c2ba0555af6bd4c28d46437fd8276c47ac4951cc SHA-256: cba5377813b1169cdfa3a9891793e2a27d26628c8cf889b439c54fb6dfe7e1f9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of PDF-specific heuristics like 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://avonsteel.com/UserFiles/file/95344594671.pdf In PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/sbvhpgqf6m7a07h2mve7pep7gv/zejununidigilokokixu.pdfIn PDF document text
    • http://nousgarage.com/userfiles/file/pamadugapojex.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a5d1733b836---7471493724.pdfIn PDF document text
    • http://zl369.net/userfiles/file/legozusisasijoniwobafot.pdfIn PDF document text
    • https://aydin-elektrik.com/resimler/files/46557341921.pdfIn PDF document text
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/70b83edbc9f580c01de18dc27d028abf/77022578416.pdfIn PDF document text
    • https://dancleland.com/img/upload/file/vebej.pdfIn PDF document text
    • http://coimbra.hu/uploads/ckfinder/userfiles/files/riduwugiduxemuwog.pdfIn PDF document text
    • http://novosib-sport.ru/ckfinder/userfiles/files/fojobofased.pdfIn PDF document text
    • https://connect.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/11c65feb0fd48093563bc7a068ef601d/rimatujogo.pdfIn PDF document text
    • https://matrainagycsalados.hu/userfiles/file/fopugitoboludowar.pdfIn PDF document text
    • https://sailstudy.in/ckfinder/userfiles/files/70108244464.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/1609c3361b691a---lowusedazifarafinemekasog.pdfIn PDF document text
    • http://thechelseaff.com/user_uploads/files/roxolefimobolesu.pdfIn PDF document text
    • http://fontanarosaserigrafia.it/userfiles/file/dofolosuvarevotagamiwupol.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1609a75cb49b0f---3090460243.pdfIn PDF document text
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f31073a08c9---vosilewazosixi.pdfIn PDF document text
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/s8eqfk94se418bv33hmjpsmgu4/84045070899.pdfIn PDF document text
    • https://robinio.de/wp-content/plugins/super-forms/uploads/php/files/7b170ruj6oj8bnnabdjg061qis/4749983408.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075e872ec8f9---94800092837.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/160fd29bac3a0d---zipotizoxopamezikusogi.pdfIn PDF document text
    • http://xn--12cm8caae5d9a0a0a1dxk6dd.com/user_img/files/vokekuni.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160df899307d9c---23504470128.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=exercice+corrig%C3%A9+pythagore+3%C3%A8me+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_off0000f05f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF05F 11428 bytes
SHA-256: 152d26cba64db0ec807c19593d8ba01c977f0d84682351015f7935ba6cbb5dac
font_01_sfnt_off00010a90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A90 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000122a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122A2 19196 bytes
SHA-256: b98348493c1f70761e916c0a512fb50803badfb5a5ef80896ba9e9185652df8c