Malicious PDF — malware analysis report

Static analysis result for SHA-256 e857f3449caf8ae2…

MALICIOUS

PDF

90.0 KB Created: 2021-08-02 12:22:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 4219422e699b9c0b2941447a31703f2f SHA-1: 732d9ca794411f0c0d67e5db2a4f2c0f74149ab0 SHA-256: e857f3449caf8ae256d35a1cce3296d2fa93e8f46c2f2fa04a672b13ff37d7ff
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URLs, many hosted on compromised WordPress sites, suggesting a phishing or malware distribution campaign. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of embedded URLs and the nature of the heuristics point towards the document being used to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://medvor.ru/uplcv?utm_term=cpt+code+for+ct+guided+needle+aspiration PDF link annotation
    • http://witnesstherealist.com/wp-content/plugins/super-forms/uploads/php/files/c92adbddb5d877549b4adc1fbf2738ea/suzikazipon.pdfIn PDF document text
    • https://www.idahomedia.com/wp-content/plugins/super-forms/uploads/php/files/917839597177ebdd8c8307dfe3e7652a/59837270345.pdfIn PDF document text
    • https://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/bf4eed0b9b7a00c87cd33549e9b8c2da/mavuditajubovugakuretezil.pdfIn PDF document text
    • https://ooo-kenk.ru/userfiles/file/vugotumovama.pdfIn PDF document text
    • https://fonixkoncert.hu/upload/file/38073760993.pdfIn PDF document text
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/b918ef81856410a348f1b96b23139da6/28149797265.pdfIn PDF document text
    • http://gute-reise.ru/i/files/files/68168806082.pdfIn PDF document text
    • http://mlkscholarshipsmilwaukee.org/clients/f/f0/f021f13c5c598389be7e913a1ae626ff/File/74020135160.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/16078e3ee2e8e7---bidimivitamoborodudel.pdfIn PDF document text
    • https://digireg.ru/upload/21805335069.pdfIn PDF document text
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1606fd0881b059---6325712832.pdfIn PDF document text
    • http://www.socalgreatwhite.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f6b12a8d01---3543973754.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/160982ff6cc2c4---bidivaboxusafe.pdfIn PDF document text
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/5a859ae4da602016298d4cf4cbf0b70c/65063710338.pdfIn PDF document text
    • http://www.themixchange.com/userfiles/files/wuvarukixoteme.pdfIn PDF document text
    • http://dush-kz.ru/uploads/fck/file/zijivixamikitesovidud.pdfIn PDF document text
    • http://cdmatik.com/uploads/file/6054205110.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/2e0f9e1594a46b3fefaef40e1e009574/92371669840.pdfIn PDF document text
    • http://xn----8sbaqfskngn1qi.xn--p1ai/userfiles/file/86005145232.pdfIn PDF document text
    • http://bongoes62.dk/userfiles/file/11559017604.pdfIn PDF document text
    • https://fullmagicweekend.com/ckfinder/userfiles/files/lasiro.pdfIn PDF document text
    • http://cetinelektrik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1608289d9ce9a6---84801612205.pdfIn PDF document text
    • http://ahlhy.com/uploads/file/010156545656.pdfIn PDF document text
    • http://heizler.hu/files/file/38069005263.pdfIn PDF document text
    • http://janyska.home.pl/_mjanyska2013/fotki/file/jodafasip.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_off0000f353.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF353 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010b65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B65 20408 bytes
SHA-256: 22df4de25fefa1f97d7fa11577bf301fee84aef0e82721193e695a0770199d58
font_02_sfnt_off00013fdc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13FDC 10928 bytes
SHA-256: af77b4765c4d4ce51a5f08b05350d690ade15d60940312639ee2abb4ffaed5a4