Malicious PDF — malware analysis report

Static analysis result for SHA-256 f548e4242745d0bb…

MALICIOUS

PDF

71.5 KB Created: 2021-09-10 18:54:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 862f2ba3815f64f6a88ad7dd652814ab SHA-1: d50694c062766b358ce88a25f9ffcc63fde48b7f SHA-256: f548e4242745d0bb884bb1765b5a9d9e5135bbde3617b26ab715fdf155949009
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and link farm heuristics, indicating its primary purpose is to redirect users to potentially malicious websites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. The presence of multiple compromised CMS upload links further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://krisoc.ru/uplcv?utm_term=call+of+duty+world+at+war+free+download+for+android PDF link annotation
    • https://sma-dfgg.org/site/admin/file/20293727755.pdfIn PDF document text
    • http://gabortech.com/admin/file/62823918883.pdfIn PDF document text
    • https://cncostruzioni.com/userfiles/file/37089176372.pdfIn PDF document text
    • http://onelove.cz/file/soluzonetowufarud.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/161358b3dbe27e---wabiruxozolekebizu.pdfIn PDF document text
    • https://thuaphatlaihoanghuy.com/uploads/files/82951133021.pdfIn PDF document text
    • https://ezsprinting.com/userfiles/file/72475176551.pdfIn PDF document text
    • http://cerritos.songhakbbq.com/uploads/files/buxodawubofikog.pdfIn PDF document text
    • http://xn----9sbkvfu2aex3d.xn--p1ai/ckfinder/userfiles/files/63542754312.pdfIn PDF document text
    • http://koopmankennedyfeller.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/5998790058.pdfIn PDF document text
    • https://fong-cai.com/upload/files/pujudasedekaxixutiwisel.pdfIn PDF document text
    • http://xn--9d0b102a6wc3y4a.com/sa_upload/userfiles/file/20210909083627.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/161305498b7222---83946348148.pdfIn PDF document text
    • https://zenmobile.in/jaipriyart/uploads/files/93916643150.pdfIn PDF document text
    • http://sirindhorn.net/upload/File/34672464194.pdfIn PDF document text
    • http://vntattoosupply.net/uploads/image/files/48272232900.pdfIn PDF document text
    • https://weborder.cloud/userfiles/file///bobutimesatogazuloxuso.pdfIn PDF document text
    • http://conhantaoankhanh.com/webroot/img/files/tobajitetujexu.pdfIn PDF document text
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/9cbe3c9d98dc7578d549bb2de51f52a0/54772193617.pdfIn PDF document text
    • https://kaparatt.com/images/File/306085556.pdfIn PDF document text
    • https://holcom-wd.holcom.vn/webroot/img/files/vinajajolelulux.pdfIn PDF document text
    • http://drentmedischadvies.nl/uploads/files/xebosatubukivelunigaf.pdfIn PDF document text
    • http://technology-mp.it/userfiles/files/33963802177.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_off0000b756.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB756 10512 bytes
SHA-256: d52b7003dff19d05df61143510b4d4430a298907023b05b21ddf70b2f55becda
font_01_sfnt_off0000cf7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF7A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e78c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE78C 15780 bytes
SHA-256: a24e9b4636626c4fa9edbcb6c1a41d6dbeda210dc13ebaea5cf5d19c5cc12da6