Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5e552a26b08d33c…

MALICIOUS

PDF

87.6 KB Created: 2021-09-23 16:21:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: c2bd16c3cdc573960a051bddbf24b31e SHA-1: 81ab7fc607c00895be52f368ec7434a07b7eb3fd SHA-256: c5e552a26b08d33cf97df51a6bf743a2c8dfb389b3dfb0eaf751a0093df6599c
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised CMS uploads and disposable hosting, indicating a link farm designed for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or trojan delivery. No scripts were extracted, but the structure and URL analysis point towards a malicious document.

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://gyuco.com/uploadfile/files/20210914_111840.pdf In PDF document text
    • http://mariopresto.pl/userfiles/file/jonodabiditomavugimapewu.pdfIn PDF document text
    • http://phrabat.net/UserFiles/File/komenikurubifo.pdfIn PDF document text
    • http://bannermaul.com/userData/board/file/20401704113.pdfIn PDF document text
    • http://creativeindustries.ru/uploads/userfiles/file/2385723048.pdfIn PDF document text
    • http://emilymillerlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/99919082725.pdfIn PDF document text
    • http://siamsankyo.com/Uploads/file/6832217211.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/qgmmb519llchk3lg2g54folngr/35113009410.pdfIn PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613947f1cdfad---rikuruwi.pdfIn PDF document text
    • https://www.uniqueartzz.com/wp-content/plugins/super-forms/uploads/php/files/mjfbeepen58g8ckosn6baa417l/moforibuvesulelegorad.pdfIn PDF document text
    • https://foundlight.ca/home/foun6192/public_html/files/custom_files/file/81805663066.pdfIn PDF document text
    • https://jaukiaplinka.lt/ckfinder/userfiles/files/zopaxubazejegojuta.pdfIn PDF document text
    • http://tasarimak.com/ckfinder/userfiles/files/xumesot.pdfIn PDF document text
    • https://villanakarin.com/userfiles/files/21952167401.pdfIn PDF document text
    • http://xn----7sbakif2a3azdub.xn--p1ai/admin/ckfinder/userfiles/files/dozonupaj.pdfIn PDF document text
    • http://thepducphat.com/upload/files/86115119705.pdfIn PDF document text
    • https://ambalatender.com/upload/files/xowasajuwoporatekedo.pdfIn PDF document text
    • https://podgoricki-klub.me/userfiles/file/45208253101.pdfIn PDF document text
    • https://tradingcall.in/ckfinder/userfiles/files/69668376481.pdfIn PDF document text
    • http://dasbluemchen.com/52428170762.pdfIn PDF document text
    • http://dongphat.net/upload/files/50891723988.pdfIn PDF document text
    • http://coeb.eu/userfiles/files/51738548775.pdfIn PDF document text
    • http://paykaaluminiya.ru/ckfinder/userfiles/files/60675495745.pdfIn PDF document text
    • https://nhabe.com.vn/ckfinder/userfiles/files/76704916417.pdfIn PDF document text
    • http://seamacros.com/upload/file/wotubufabapopamole.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=android+game+warPDF 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_off0000f4e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4E5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010cfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CFC 10344 bytes
SHA-256: 4cdf4fad4b5c30df83ca24c91bd2ad049ed54a22c20cced3242d25456e0484c4
font_02_sfnt_off0001241c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1241C 17396 bytes
SHA-256: 6d74d8d3a0c052ec7de2275157eae0964593d8c219e1de0048a7c6832e100064