Malicious PDF — malware analysis report

Static analysis result for SHA-256 313c4b6a5abaf34b…

MALICIOUS

PDF

69.5 KB Created: 2021-10-04 07:53:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: f3f8938287dbfc22bd8fd28b3b5b6ff2 SHA-1: 09ff854d725ef47492df66619c0bf5b850f6551c SHA-256: 313c4b6a5abaf34ba8e70bed314628ac5c3278faf066c795045cb7349875a74d
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many of which point to compromised websites or disposable hosting, indicating a link farm designed for malicious redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the structure and URL analysis point to a common tactic of using documents to host redirectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://atol-res.pl/uploads/file/53233401611.pdf In PDF document text
    • http://bananamusic.tw/uploads/files/202109250348455660.pdfIn PDF document text
    • https://onecre.com/images/content/files/guburasepef.pdfIn PDF document text
    • https://maribon.net/app/webroot/files/userfiles/files/79412084436.pdfIn PDF document text
    • https://yellowstonewildlife.com/pifunikalukikosux.pdfIn PDF document text
    • http://cnpair.com/userfiles/file/66073800723.pdfIn PDF document text
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/f6085a9af6f11032c76abe3f2853fb57/semomuvovame.pdfIn PDF document text
    • http://master-br.ru/img/file/75715242981.pdfIn PDF document text
    • http://starma.pl/files/file/jalexaxarisiludozixefupor.pdfIn PDF document text
    • http://wittlich-luexem.de/userfiles/file/laliler.pdfIn PDF document text
    • https://centaur.vri.cz/docs/files/74377132677.pdfIn PDF document text
    • http://belovosushi.ru/files/zukujeget.pdfIn PDF document text
    • http://fxlcd.com/upload/file/67276821904.pdfIn PDF document text
    • https://profix.fr/ckfinder/userfiles/files/3640355288.pdfIn PDF document text
    • http://speakingaboutnetworking.com/ckfinder/userfiles/files/14300321118.pdfIn PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161357dd80ea07---3451675459.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613e8101ac61d---nomapelomo.pdfIn PDF document text
    • https://zhbiotech.com/CKEdit/upload/files/sikulewav.pdfIn PDF document text
    • http://klusjesindex.nl/images/uploads/mexazowiwesikarino.pdfIn PDF document text
    • http://pomelieagency.com/userfiles/files/43999707335.pdfIn PDF document text
    • https://zlatartopalovic.rs/files/fulita.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=standard+medical+records+release+formPDF 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_off0000ae0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE0A 10712 bytes
SHA-256: f33775f1942c86f7f5701a370d964f6e071abb93219c60ea79315572cbd60337
font_01_sfnt_off0000c68f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC68F 16472 bytes
SHA-256: 35c272b37913c02349bf23b4bb5ab4907f7ba275224f8a29cc54cc56f1437ebb
font_02_sfnt_off0000f060.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF060 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1