Malicious PDF — malware analysis report

Static analysis result for SHA-256 187a18f8e0a79135…

MALICIOUS

PDF

84.6 KB Created: 2021-10-18 09:15:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 1614faf621f3a69c528643f0a7344dfd SHA-1: 7e4aa8817db19928b83faedc4a6e3cfb82bd37db SHA-256: 187a18f8e0a7913507434fe4eff4fe041ccb5ca96b88427bdcc68ee401a2f6cb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

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://asiastudy.in/ckfinder/userfiles/files/muvolofitefupogolokizajab.pdf In PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/161431b7723dca---85550844331.pdfIn PDF document text
    • http://ksiclubbiz.ksiclub.org/svnprojects/DHD/Source/images/files/6658292225.pdfIn PDF document text
    • https://otoform.com/upload/ckfinder/files/26982194453.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/16151b07567ebb---butalani.pdfIn PDF document text
    • http://yingtailong.com/upload/file/210927150007367120xcgaahwwlnlm.pdfIn PDF document text
    • http://ingmarcofaedi.com/userfiles/files/tolelimebowino.pdfIn PDF document text
    • http://trungtamdaykem.vn/Images_upload/files/37499542367.pdfIn PDF document text
    • http://tianlanip.com/filespath/files/20210903210325.pdfIn PDF document text
    • http://ks-system.co.uk/ckfinder/userfiles/files/18747621782.pdfIn PDF document text
    • http://busto-wl.gattinonimondodivacanze.it/themes/userfiles/files/57400487342.pdfIn PDF document text
    • http://jjw-led.com/userfiles/file/15332912086.pdfIn PDF document text
    • http://sjatupornservices.com/file_media/file_image/file/xijosaruvurozunuxorotar.pdfIn PDF document text
    • https://perkunasstudio.com/uploads/files/202109301818584168.pdfIn PDF document text
    • http://technocom.pl/editor/file/tukepokenisaxojufafimobet.pdfIn PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/16159a61d8931d---97067170476.pdfIn PDF document text
    • https://proxus.nl/file/83939096267.pdfIn PDF document text
    • http://divinescience.in/userfiles/file/45890958713.pdfIn PDF document text
    • https://chatham-ebenezer.ckdomain.com/uploads/userfiles/files/94685016306.pdfIn PDF document text
    • https://gmnavarra.es/ckeditor/files/97065348524.pdfIn PDF document text
    • http://yongqingtech.com/d/files/66679561651.pdfIn PDF document text
    • http://feedproxy.google.com/~r/MbOu/~3/7xhmvLXWVJc/uplcv?utm_term=whitetail+shed+huntingPDF 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_off0000e918.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE918 10400 bytes
SHA-256: 2cd31db4724306344096720f6183732b12fae261fe9ba2133e57a704c9f1ff89
font_01_sfnt_off00010052.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10052 17224 bytes
SHA-256: d56e4872e2dc376b08456a8d59821889f05c5c64a9951e56f263873d383989c9
font_02_sfnt_off00012cfa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CFA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1