Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac20994a3f57fd7b…

MALICIOUS

PDF

90.3 KB Created: 2021-07-03 17:14:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 33c49d24ae30374d669f8232eb6cc3e4 SHA-1: ce44d6bafa12a8deb4a13db40ff94efce121141e SHA-256: ac20994a3f57fd7b9d47414ad423517177387ad1c7d1b520126f37765e7a9c34
156 Risk Score

Malware Insights

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

The sample is a PDF document identified by ClamAV as Pdf.Phishing.Trojan. It contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable domains, suggesting a link farm designed to lead users to malicious content or phishing pages. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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=soa+to+microservices+migration PDF link annotation
    • https://flardochform.se/userfiles/file/526085187.pdfIn PDF document text
    • https://deedpoll.sg/wp-content/plugins/super-forms/uploads/php/files/1053ae9e1093cea43cb657e01723f246/56048480129.pdfIn PDF document text
    • https://sp-pir.ru/wp-content/plugins/super-forms/uploads/php/files/12381a642f023b1d16628b1c56618268/guvawitakolelasidenoru.pdfIn PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/68936a779b982231736ae6e5fbc85d6b/luneladu.pdfIn PDF document text
    • http://bjhtdszdh.com/v15/Upload/file/202172155329865.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/ed1e46bb7ac53221eb802c8b3b969a5c/kolenugujaxijuwadot.pdfIn PDF document text
    • https://bisnismedsos.com/userfiles/file/26656728769.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/16073f740dedbc---90163659228.pdfIn PDF document text
    • http://terapeutickemasaze.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1609ac4fa95af1---14909659708.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/d1464a04b533e75901fec2da514f330a/15409225830.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/068e006b23af7a7cf2110e28b0816645/tewigutuvebijitubup.pdfIn PDF document text
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607734f3e1292---xegegudevu.pdfIn PDF document text
    • https://karapinarinsaat.net/userfiles/upload/file/nokitojojijakibekelokalu.pdfIn PDF document text
    • http://lavalnerina.it/userfiles/file/xatojafimiwidarefinaditon.pdfIn PDF document text
    • https://fiambreszav.com/wp-content/plugins/super-forms/uploads/php/files/82a1d69d09f4c1a0e362d01e5e6f82fe/22960887762.pdfIn PDF document text
    • https://apskarota.org/userfiles/file/porekararofaxokalowezub.pdfIn PDF document text
    • https://agilitynd.com/wp-content/plugins/super-forms/uploads/php/files/6ec76c5fa383254baca0aded7bcc61bb/53455161619.pdfIn PDF document text
    • http://ehhs1969.com/clients/6/67/67a0fa02f482ea8575b7cec7429e43a8/File/87831349766.pdfIn PDF document text
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/bde0f9ad1e41baf8a9802c4bcb1a622e/7713898295.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b07c64f1704---83868519982.pdfIn PDF document text
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa6d52dbd2d---firemekatelajotelevemag.pdfIn PDF document text
    • http://pericosrentcar.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160ae9057647af---lojezoles.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16095626341f0a---90349352542.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a3b6c1742c9---54581796693.pdfIn PDF document text
    • https://koetec.com/home/~ptow/public_html/ckfinder/userfiles/files/xenogewiginowegigam.pdfIn PDF document text
    • http://lovewhereyoulv.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/a48a36e0d83daef759e1fea6fa8a612b/87775445651.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_off00010017.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10017 16872 bytes
SHA-256: 7eb8c638089c73cf42a4c7b88176a4d1464da9a068e40d3f25bf7f34718f5baa
font_01_sfnt_off00012b52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B52 10668 bytes
SHA-256: 58217b5de78b93b1c906a2ad77b7534f71c1517f61bd2ef4daaa9b64cc6dd173
font_02_sfnt_off000143c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x143C8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1