Malicious PDF — malware analysis report

Static analysis result for SHA-256 753831dc7131a9f3…

MALICIOUS

PDF

79.4 KB Created: 2021-09-20 05:48:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 102615bc8b15c9336d85e12ac8b434e7 SHA-1: 5ea4e9093010e76b9d534a61cc2c81b76ce89abd SHA-256: 753831dc7131a9f3810a63e2f7f5d73211dede0482ad68326707a3744e3e6a63
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed to distribute traffic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://laskod.hu/userfiles/file/83191931919.pdf In PDF document text
    • http://cermak-expo.cz/data/files/file/dedon.pdfIn PDF document text
    • http://precisao.org/files/files/lanuxopaturemub.pdfIn PDF document text
    • http://emanuelarombiarchitetto.eu/userfiles/files/zedamoriwozibirabatude.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/16141a4c315e0e---48074062411.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/zaferinuwipovomefa.pdfIn PDF document text
    • http://daphongthuyhueminh.com/uploads/image/files/potubajikodif.pdfIn PDF document text
    • http://aburobocon2019.mnb.mn/uploads/files/18528567384.pdfIn PDF document text
    • http://shangrilatheshow.com/ckfinder/userfiles/files/topulamulimamamafo.pdfIn PDF document text
    • http://hyundaiokla.com/uploads/files/84525889098.pdfIn PDF document text
    • https://lescourailleurs.com/upload/editor/file/68174756164.pdfIn PDF document text
    • http://www.goldenlantern.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161467ce0ad534---63174834435.pdfIn PDF document text
    • http://kaies.cn/upfiles/210917054159377814ax1cy9.pdfIn PDF document text
    • https://www.zaantraining.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16130c0b53eb12---72704534667.pdfIn PDF document text
    • http://ultraljud.nu/bild/files/87470825517.pdfIn PDF document text
    • http://japanbizkorea.com/userData/ebizro_board/file/25609925.pdfIn PDF document text
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/cc4d6d8903a1221b674736c1802cc8b7/koxorukakujupusatovilena.pdfIn PDF document text
    • http://malir-naterac.info/UserFiles/File/70723504348.pdfIn PDF document text
    • http://ideviceplus.be/app/webroot/files/userfiles/files/50159095346.pdfIn PDF document text
    • http://rasciindia.com/firetech/ckupload/files/ximerumojes.pdfIn PDF document text
    • http://www.roosprommenschenckelfoundation.nl/ckfinder/files/files/boziminamegijejanaxogixa.pdfIn PDF document text
    • https://diphong.com/uploads/30916623346.pdfIn PDF document text
    • https://funke.be/data/file/ridapapatililitifikax.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=vpn+pubg+lite+downloadPDF 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_off0000cc1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC1C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e42e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE42E 20212 bytes
SHA-256: ef6725a0eb26d2b1e47e1930e46653590de0027375d15c0045fcce00c72fee1d
font_02_sfnt_off0001188b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1188B 10596 bytes
SHA-256: 391d3674c1d64800224d3eb4b755c53f0cad59e482551433a56f4e1cb0c720f2