Malicious PDF — malware analysis report

Static analysis result for SHA-256 f829f2e274f82d17…

MALICIOUS

PDF

79.0 KB Created: 2021-09-17 18:28:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 7bb5599d3acff92bf61a2b254864e65f SHA-1: 1fb99c3d1bb6a7d4473451432438aeda4f831d0a SHA-256: f829f2e274f82d17d1257384c2bf3af99d4fe2b61c5856fc2fea284a7dbd3c51
156 Risk Score

Malware Insights

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

The PDF document was flagged by multiple heuristics as malicious, including a ML classifier and ClamAV, indicating it is likely a phishing or malware distribution lure. The heuristics identified it as a link farm pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious sites. No scripts were extracted, but the presence of numerous unknown URLs strongly supports the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://dichvuketoansg.com/luutru/files/14042018203.pdf In PDF document text
    • http://7sate.com/filespath/files/20210908080332.pdfIn PDF document text
    • http://xn--38-mlcqjbufcz6h.xn--p1ai/userfiles/file/zejelububeliviruzagi.pdfIn PDF document text
    • http://mwflower.com/upimagesfile///nunonekaxo.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16141432d4a6e9---53387627924.pdfIn PDF document text
    • https://jogamiskolc.hu/ckfinder/userfiles/files/41462884227.pdfIn PDF document text
    • http://dakmoto.cz/obrazky/file/tisokegivulepifezux.pdfIn PDF document text
    • http://cokhihoaiduc.com/uploads/files/kofezotisebifekujuxuj.pdfIn PDF document text
    • http://studioaba.net/userfiles/files/kifonubevagexo.pdfIn PDF document text
    • http://xaydunganphubacninh.com/webroot/img/files/40760611353.pdfIn PDF document text
    • http://terredellamagnagrecia.com/userfiles/files/notab.pdfIn PDF document text
    • http://reliancefla.com/admin/images/file/95858801890.pdfIn PDF document text
    • http://mamnonkitty.com/webroot/img/posts/files/55056810938.pdfIn PDF document text
    • http://cesarrodarte.com/userfiles/file/gusarebalujopisipisi.pdfIn PDF document text
    • http://salman-is.com/userfiles/file/lulolukugopibave.pdfIn PDF document text
    • http://syntrend.critical.tw/upload/files/36875065309.pdfIn PDF document text
    • https://remini.hu/userfiles/file/butirijegoxovevoza.pdfIn PDF document text
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/45303292443.pdfIn PDF document text
    • https://suksesunited.com/contents/files/14214976553.pdfIn PDF document text
    • http://erbaytag.com/resimler/files/1581487831.pdfIn PDF document text
    • http://tmtechvn.com/webroot/img/files/futivinoromevujovagomun.pdfIn PDF document text
    • https://akconta.com/uploads/files/76929733382.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/99b75cc0a938e35a2444078cc8a5c1f6/2742354773.pdfIn PDF document text
    • http://arredamenticucinesiciliane.it/userfiles/files/70008944885.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/161305fded856f---17809683485.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=closer%27s+survival+guide+pdfPDF 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_off0000d0a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0A7 10700 bytes
SHA-256: 6072d1d477ad59f418660cc6b2c18e8604bf2e2bf2ddf3ab832d984e748a7aa5
font_01_sfnt_off0000e929.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE929 17404 bytes
SHA-256: b5caf594027c218d98c6c748311b80caa201d3f262e4202788c27480e9a97a5a
font_02_sfnt_off00011610.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11610 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1