Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b2b09b9990b44b3…

MALICIOUS

PDF

80.7 KB Created: 2021-09-20 15:01:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f39604bf123ddc860faab0754cf4a70a SHA-1: 54286692d7c56d106a7c85f8faf383bfba05cfef SHA-256: 3b2b09b9990b44b3c8627ca44182b07e09beb1e21e6c6dd76f41cf43f249f186
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, with multiple URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to distribute further malware or conduct phishing. The presence of numerous external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://maychieuvinh.vn/upload/files/larulaxebunukaraxo.pdf
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146760347d1a---70539273103.pdf
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16147394fe731b---90673562603.pdf
    • http://gruaszarate.com/ckfinder/userfiles/files/12762415353.pdf
    • http://velapower.com/glwh/UploadFile/file/2021091905043073499.pdf
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613c85578d41a---57908034740.pdf
    • http://wildzipper.com/clients/wildzipper/userfiles/file/69527914725.pdf
    • https://clinicscrm.com/img/files/79651122734.pdf
    • http://incomingmakedonia.com/files/files/53418280472.pdf
    • https://truckforceone.com/upload/editor/file/47034080479.pdf
    • http://feriaalainversa.com/uploaded/files/mokuzok.pdf
    • http://urbanconstructions.org/images/uploadedimages/file/gelasaxezoxiror.pdf
    • https://digireg.ch/upload/4514477705.pdf
    • https://goodluckfishing.com/ckfinder/userfiles/files/dabediruzalewow.pdf
    • http://villahetzwartepaard.nl/survey/userfiles/files/99442315056.pdf
    • http://biaikatolikus.hu/files/file/gejitutuxawexetilos.pdf
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/kp3fgus0ddprpe994ldrddokv1/dilek.pdf
    • https://tims.ro/ckfinder/userfiles/files/39497225607.pdf
    • http://acsalma.hu/userfiles/files/11994680445.pdf
    • https://isleo.com/i_photos/file/nobuwoninuruxagev.pdf
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16141dedd9e015---15115693002.pdf
    • http://rideabikenews.com/user_img/files/77205664355.pdf
    • http://klinok-saintp.ru/files/20879370732.pdf
    • http://www.mariabeckmann.com/fotos/uploads/files/75498599650.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=lan+driver+for+windows+xp+32+bit
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d5b6.bin
36199d7cef36bfb486bc17bc4051ad295af181851a98f6c45a74bfbeecf20494
pdf-font-stream PDF embedded font (sfnt) at offset 0xD5B6 17444 bytes
font_01_sfnt_off000103a6.bin
920bb68f5cc85b01fef20d07e0eb47eefdf82d272117ba4af7824ac4b21ec422
pdf-font-stream PDF embedded font (sfnt) at offset 0x103A6 11088 bytes
font_02_sfnt_off00011d8a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D8A 16792 bytes