Malicious PDF — malware analysis report

Static analysis result for SHA-256 fbcae6cce0de651b…

MALICIOUS

PDF

79.1 KB Created: 2021-09-13 13:36:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 7b4013be2bed34d0db31ea0db72c0dd9 SHA-1: 06651b9bec42c24418f775e6a11ff81ee2be10de SHA-256: fbcae6cce0de651b19e430ad359ab93d3e60091c18f6b4c6937aa4f5f07ed4c2
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and links to compromised CMS uploads, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The presence of multiple distinct hosts and UTM parameters in URLs points towards an effort to obscure the final destination and potentially track user engagement.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://pistant.ru/uplcv?utm_term=thunder+vpn+apk+free+download PDF link annotation
    • http://homeopathyhongkong.org/files/53095161274.pdfIn PDF document text
    • http://checopharma.com/upload/files/59228447972.pdfIn PDF document text
    • http://www.ssc-ras.ru/ckfinder/userfiles/files/zumekupotojukivu.pdfIn PDF document text
    • http://dulichtantai.com/files/uploaded/files/59952808025.pdfIn PDF document text
    • http://graviroz.hu/ckfinder/userfiles/files/pifesadixofokijiror.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613caa641270d---dapubiwelotogogosodew.pdfIn PDF document text
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16133293caaaab---fapobidefutuxowaga.pdfIn PDF document text
    • https://bunian-co.com/other_files/File/90168612191.pdfIn PDF document text
    • https://heritagecambodiatravel.com/userfiles/file/goritugix.pdfIn PDF document text
    • https://martabaktelor.com/contents/files/tuwumavot.pdfIn PDF document text
    • https://www.lsv-wittlage.de/ckfinder/userfiles/files/15410053466.pdfIn PDF document text
    • https://windfreeklima.com/upload/ckfinder/files/lesapozijunage.pdfIn PDF document text
    • http://sungwoo-n.com/userfiles/file/66614212797.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/b8130aa0aa7531a255ecc984a318ec25/63239073589.pdfIn PDF document text
    • http://bhk-aindling.com/userfiles/files/wixopiwozogagovolefab.pdfIn PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/ecdf3bdedd416271ff4e14a718d5a0f7/boxotasulogaroxudolenoje.pdfIn PDF document text
    • https://srccaa.bdbabymart.com/app/webroot/ckfinder/userfiles/files/19187733353.pdfIn PDF document text
    • http://guchen.ru/d/files/zufagiveg.pdfIn PDF document text
    • http://speaklifeiamgreatness.com/files/files/42409030282.pdfIn PDF document text
    • http://logopeda-empatia.pl/content/file/nivawaralevunibufuzet.pdfIn PDF document text
    • http://www.salpasafarit.fi/tiedostot/files/1059369005.pdfIn PDF document text
    • https://vntdc.com/upload/fck/file/90300634827.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_off0000ca00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA00 10544 bytes
SHA-256: 4682dd0513f2163f1193fdb349649c3c7df4cc7ba29981dafc1b1b1e70d63a93
font_01_sfnt_off0000e1fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fa0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA0E 19808 bytes
SHA-256: f26bce308f74d99fe059182a8cab4b6e4862950916ba3fbe7088b9c2e64346c3