Malicious PDF — malware analysis report

Static analysis result for SHA-256 41535d7754b62c47…

MALICIOUS

PDF

90.3 KB Created: 2021-08-07 07:38:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 592e109ae86ca2fadd7439527dbf87a3 SHA-1: 6a79908a2fb68f0315cf33c58e94f403837be095 SHA-256: 41535d7754b62c4766cc3de02382c6cbc978ad5a983c8bd20baf1d68e9db7c5b
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to compromised WordPress upload storage and other disposable hosting. These links likely lead to further malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://cityfate.com/files/files/23206674275.pdf In PDF document text
    • http://baigeleather.com/userfiles/file/voxasuzatugu.pdfIn PDF document text
    • https://www.tyrtaios.gr/ckfinder/userfiles/files/39262259593.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16098ae13a6d19---61613717038.pdfIn PDF document text
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/6e9f62906dd7941f35ec8ba33d5e9a5f/13645641288.pdfIn PDF document text
    • http://ahdongjiu.com/upload_fck/file/2021-5-1/20210501211944721563.pdfIn PDF document text
    • http://geteffective.biz/uploadfiles/file/vepibikulepofavow.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/160748d173d5be---polex.pdfIn PDF document text
    • http://jplus-ag.com/upload/files/BodyFile__60D4C121C4EDF.pdfIn PDF document text
    • https://responsible-tourism-alliance.com/content_file/files/zesegofukizozebubulafas.pdfIn PDF document text
    • http://massimosusto.eu/userfiles/files/nigopetid.pdfIn PDF document text
    • http://hzbaoyan.com/images/upload/File/46572959616.pdfIn PDF document text
    • https://autosaloncenter.com/uploads/files/gutuzop.pdfIn PDF document text
    • http://synergytaekwondo.com/click2buy_newp/userfiles/file/63701149960.pdfIn PDF document text
    • https://imagebuzz.net/ckfinder/userfiles/files/89572287364.pdfIn PDF document text
    • https://inchiriereelicoptere.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160870ca4a4a1b---zozukazetifubapisel.pdfIn PDF document text
    • https://www.aceitedeoliva.com/wp-content/plugins/super-forms/uploads/php/files/285e208eaa6c0209c57d3bc9408b9f8c/wovot.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/160ae4e42d39ee---17787030025.pdfIn PDF document text
    • https://ropaalmayoreo.com/images/userfiles/file/palozuwanelumo.pdfIn PDF document text
    • http://ahxxzx.com/userfiles/202105/file/ramesijak.pdfIn PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c61c2a11fc---3379218220.pdfIn PDF document text
    • http://bjaimama.com/data/upload/2021/06/file/202106130017484644.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/920f4fa50f7dade1b948f292da2dac99/98112335171.pdfIn PDF document text
    • http://alexandersorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/18878157513.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=extremely+loud+and+incredibly+close+actorsPDF 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_off0000faff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAFF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011316.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11316 10968 bytes
SHA-256: ef54825a62a90355275a869c7828bbc0e6f7f0c83253973a45339cc8bc41de13
font_02_sfnt_off00012c8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C8B 18184 bytes
SHA-256: 4a68a6e4aeccecf6c89e5c210244bf432f8abf719b9f0e19618c9ebac8f25f68