Malicious PDF — malware analysis report

Static analysis result for SHA-256 50e61a0c23a3198b…

MALICIOUS

PDF

97.0 KB Created: 2021-10-08 10:18:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 78139a0658b87b3f8873172ad80f4406 SHA-1: 2f8179505389416196fcdb5293796f7fcd2d3f6b SHA-256: 50e61a0c23a3198b46b548a9862d1ef5f67d8e05ea1d85464a36416656af2b63
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by a ClamAV detection and an ML classifier. It contains numerous embedded URLs that form a link farm, with several pointing to compromised CMS upload storage. The primary function appears to be directing users to potentially malicious external websites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614eb9f2c1fdf---99282654349.pdf In PDF document text
    • http://aristosaigonhotel.vn/uploads/files/47475757272.pdfIn PDF document text
    • https://motoralbini.it/files/file/30971778181.pdfIn PDF document text
    • https://asiastudy.in/ckfinder/userfiles/files/3840438898.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614112be92a2d---fikadotenarenogizumi.pdfIn PDF document text
    • https://samsungklimamodelleri.com/upload/ckfinder/files/dasezofatisido.pdfIn PDF document text
    • https://attackworkoutprogram.com/app/webroot/files/ckfinder/userfiles/files/69929923297.pdfIn PDF document text
    • http://fixafilm.se/userfiles/file/52723808188.pdfIn PDF document text
    • https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147f56987efd---jedefidab.pdfIn PDF document text
    • http://ventss.ru/userfiles/files/25885622842.pdfIn PDF document text
    • https://inprovitecuador.com/ckfinder/userfiles/files/87119896722.pdfIn PDF document text
    • http://gaia-onlus.org/userfiles/file/denib.pdfIn PDF document text
    • http://zhihepvb.com/upload/ckimg/files/202110080908359741.pdfIn PDF document text
    • https://vinamex.info/uploads/news_file/noruwuxol.pdfIn PDF document text
    • http://associatedreclaimed.reclaimedoils.com/userfiles/files/mekelumuregifez.pdfIn PDF document text
    • http://scales-center.com/shop/fck_file/file/luvipimugijemenuxopu.pdfIn PDF document text
    • http://slavicchurchmississauga.com/fck_upload/file/96092235018.pdfIn PDF document text
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/770aa4e507322a7c65ff8e9d000c5a35/52192376341.pdfIn PDF document text
    • http://bakersfield.thepokeluau.com/uploads/files/ribiwudofoweteba.pdfIn PDF document text
    • https://ecableapp.com/FCKeditor/FCKimgUpload/file/97518688960.pdfIn PDF document text
    • https://em.heephong.org/ethnicminorities/cmsadmin/ckfinder/files/38834669758.pdfIn PDF document text
    • http://tallygroupkwt.com/uploads/file/42309311325.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/1614b529cf16b0---fadenatotokovapepukuwel.pdfIn PDF document text
    • http://lamgi.pl/ckfinder/userfiles/files/xebezunawadexemejelozunix.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=to+be+affectedPDF 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_off0001152e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1152E 19112 bytes
SHA-256: 7e2119d772a8174ea1dfd43e8dc2c32e24b68d4b3fe9d775b3cba043aa83bd33
font_01_sfnt_off000147df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x147DF 10060 bytes
SHA-256: 03a7aef1d7204f02f0761d36fbf01dda2b4882b8b9554b1adee08bad92d14945
font_02_sfnt_off00015e66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15E66 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1