Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a18919fff1eaaf0…

MALICIOUS

PDF

83.4 KB Created: 2021-09-13 07:26:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c188e3848d51030370e96f3c83369482 SHA-1: d77d83afa822fe06d5812384c0df2c69b4f28567 SHA-256: 1a18919fff1eaaf0e68f333cb772102afbb4ce61c4b465d7b4a142b37270d827
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many of which point to disposable hosting or compromised CMS uploads, indicative of a link farm designed to redirect users to potentially malicious sites. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution via these links. No scripts were extracted, and the document body was unreadable, so the primary attack vector appears to be the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://dxczx.com/ckfinder/userfiles/files/20210909_000728.pdf In PDF document text
    • http://refinerlink.com/userfiles/file/didugibesefapilejadagike.pdfIn PDF document text
    • http://tao-ssct.org/data/upload/file/35902379595.pdfIn PDF document text
    • http://mebelhotel.ru/userfiles/files/91531561646.pdfIn PDF document text
    • http://chiari-web.com/ckfinder/optimist/files/xilunojezixijorusujazep.pdfIn PDF document text
    • https://hobbyschuurtje-webwinkel.be/images/userfiles/file/10726235282.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613eaf679d678---82574588834.pdfIn PDF document text
    • http://geojeoceanhotel.com/userfiles/file/20210904160101.pdfIn PDF document text
    • http://nujhimachal.in/img/uploads/files/74453412127.pdfIn PDF document text
    • http://agilesolutions.in/uploads/xapukimetaxuli.pdfIn PDF document text
    • https://cezartravel.hu/userfiles/file/96849893693.pdfIn PDF document text
    • https://www.netcorp.hu/data/editorfile/87616055227.pdfIn PDF document text
    • https://www.aironface.com/wp-content/plugins/super-forms/uploads/php/files/993bd1f25e89b7737e154e73b7441945/dolopik.pdfIn PDF document text
    • https://rowsontw.com/shopadmin/upload/files/vifuvi.pdfIn PDF document text
    • http://diskacme.dk/images/upload/file/tifavowenupagaputu.pdfIn PDF document text
    • https://coherence.cz/userfiles/file/visisudagasafi.pdfIn PDF document text
    • https://cuatudongsaigon.vn/uploads/files/67964032274.pdfIn PDF document text
    • http://moristas.com/userfiles/files/65292659953.pdfIn PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/161304fdea0eac---madozek.pdfIn PDF document text
    • http://thrifty-uy.com/files/others/79966635747.pdfIn PDF document text
    • http://www.pilatesyoga.hr/files/files/37979372170.pdfIn PDF document text
    • http://trips-in.com/ckupload/files/91654123032.pdfIn PDF document text
    • https://fontaine-eva.fr/userfiles/files/4063434762.pdfIn PDF document text
    • http://nhatrangpalace.net/app/webroot/upload/files/13758786368.pdfIn PDF document text
    • https://mps-india.com/userfiles/files/23168612953.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=how+to+move+apps+from+phone+storage+to+sd+cardPDF 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_off0000de80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE80 11072 bytes
SHA-256: 0dbe5f3b901b670d7a565cd77bffc34b95d662c5ab599866113b70721c19c175
font_01_sfnt_off0000f7f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7F6 18192 bytes
SHA-256: cff41e492414f4558f9874fff7779c054a6f7647874b40053cebc5d95f454176
font_02_sfnt_off00012794.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12794 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1