Malicious PDF — malware analysis report

Static analysis result for SHA-256 c387f8da25934d2d…

MALICIOUS

PDF

74.6 KB Created: 2021-09-20 02:45:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: ea8d96b12dd0a0d6ddb1002c297d381d SHA-1: 693799d4e16095a3c3d1cb009ca0b6e50bdc2e84 SHA-256: c387f8da25934d2da64d29270e7e4e33cd6ee092a4d50e469744c780f28d0761
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external links, including one pointing to a compromised WordPress upload, and another using a UTM term redirector, suggesting it's part of a link farm designed to lead users to potentially harmful content. The primary attack pattern involves directing users to external URLs, likely for phishing or to download further malicious payloads.

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://smidgel.ru/uplcv?utm_term=brawl+stars+mod+apk+latest+version+download PDF link annotation
    • http://dynamicyunnan.com/ckfinder/userfiles/files/ronaruro.pdfIn PDF document text
    • http://joyear.com/ckfinder/userfiles/files/rovir.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614122e7081cc---63698611285.pdfIn PDF document text
    • https://badrivishal.com/media/52035399059.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/16134220e3da53---lonemewedowovoguroxo.pdfIn PDF document text
    • https://adtw1.elfjane.com/ckfinder/userfiles/files/62499760622.pdfIn PDF document text
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/8ad6bad19c2a13250bb9f7960b26fb16/jozozikoxopuninoku.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/ffb2ebd88bd3a47a9c462e23a80ff41a/fikoberu.pdfIn PDF document text
    • http://dryoucosmeceutical.com/userfiles/files/wiziwiriborebaju.pdfIn PDF document text
    • http://premiumcsp.com/uploads/files/21357225090.pdfIn PDF document text
    • https://1000families.eu/userfiles/file/vedolelowo.pdfIn PDF document text
    • https://costabravas.com/uploads/localidades/files/57087454534.pdfIn PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b3069ba37d---ganewe.pdfIn PDF document text
    • https://bodymason.com/user_uploads/files/35077032617.pdfIn PDF document text
    • http://imhome-listings.com/userfiles/files/kiraxuso.pdfIn PDF document text
    • http://rickgrisolia.com/userfiles/files/veteziwabi.pdfIn PDF document text
    • https://shindah.com/images/ckeditor_img/files/pimusemiwiwa.pdfIn PDF document text
    • https://forexinc.ca/upload/editor/file/78900820796.pdfIn PDF document text
    • http://carbonelite.ru/file/retiwobi.pdfIn PDF document text
    • http://uptownherndon.com/uploads/files/ritufamatuwidelawidil.pdfIn PDF document text
    • https://iqrainternationalschool.org/_assets/files/gadene.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_off0000bf71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF71 17224 bytes
SHA-256: 8c822743d37adc5bec558098d5438999e87861007763aab7c6b5b52aedd02e8b
font_01_sfnt_off0000eb88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB88 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001039f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1039F 10852 bytes
SHA-256: 0b4a0ad48d3cf9cb66b10993bb1cc97fd0643b3fe9dfd62ca1b0551382fa1d19