Malicious PDF — malware analysis report

Static analysis result for SHA-256 110c3c518dd4b397…

MALICIOUS

PDF

81.6 KB Created: 2021-09-08 18:42:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 6431c8e5efb5740a486db3472daf3458 SHA-1: 2d070d741e134b557cf8ed4f273621bdcaef0a86 SHA-256: 110c3c518dd4b3971bf4c357f33973f8a83403517279d0b82d2b618d22f023ae
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Several heuristics point to the file being a link farm hosted on potentially compromised or disposable domains, designed to redirect users to malicious content. The presence of external URIs and the 'Urgency/Deadline Lure' heuristic suggest a phishing attempt to trick the user into clicking links that likely lead to the download of a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613246f082672---91533717386.pdf In PDF document text
    • https://tpk-m.ru/files/file/62772685869.pdfIn PDF document text
    • http://orthocarecentroortopedico.it/userfiles/files/bovoj.pdfIn PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/a7f6ac0b8ad4060babee2f5b2b9b24a2/79882936029.pdfIn PDF document text
    • http://studioriboldi.eu/userfiles/files/wesogefuwitidetuzirujiso.pdfIn PDF document text
    • http://phanphoiongnhuahoasen.vn/upload/files/49489781904.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137c7cda0127---valitolutivojeze.pdfIn PDF document text
    • https://ocw.tw/uploads/files/35009534212.pdfIn PDF document text
    • https://johanbjerke.se/userfiles/file/96177811580.pdfIn PDF document text
    • https://sonntag-immobilien.lu/userfiles/files/nekasolasovo.pdfIn PDF document text
    • http://execdentalclinic.com/uploads/ckfinder/userfiles/files/dedopidovax.pdfIn PDF document text
    • http://xedaptheduc.net/app/webroot/uploads/files/folimage.pdfIn PDF document text
    • http://tinhdauvietnam.vn/upload/files/3135808522.pdfIn PDF document text
    • https://aquaprosmart.com/userfiles/files/61874153392.pdfIn PDF document text
    • http://twozonechickenlasvegas.com/uploads/files/94874549082.pdfIn PDF document text
    • http://tce.vn/imagesflashupload/file/98219488361.pdfIn PDF document text
    • http://slkuang.com/v15/Upload/file/202194748595283.pdfIn PDF document text
    • http://weorderfood.com/uploads/files/wefixipukatiw.pdfIn PDF document text
    • http://enotecagaribaldi.it/userfiles/files/41081615348.pdfIn PDF document text
    • https://peptidturkiye.com/ckfinder/userfiles/files/27830209203.pdfIn PDF document text
    • http://dtmaso.com/public_html/Imagens/file/fuwasabukidojowa.pdfIn PDF document text
    • https://backcountryplayground.com/wp-content/plugins/super-forms/uploads/php/files/159575e90c40972118fd238c67e3ab82/33006246944.pdfIn PDF document text
    • http://mallenmediations.com/mallenmediations/images/userfiles/file/75861911451.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=ccrt+culture+notes+pdfPDF 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_off0000dafe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAFE 10488 bytes
SHA-256: 4a400d7fb83a856da61ac42f666d7bed9559440c90cdadfa70d54ca21b7db256
font_01_sfnt_off0000f2fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2FE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010b10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B10 17780 bytes
SHA-256: 9670def5a40beba56caa9711eee2aef074c63335df198376191388bf138542a5