Malicious PDF — malware analysis report

Static analysis result for SHA-256 b83c6ed98a9c6997…

MALICIOUS

PDF

84.0 KB Created: 2021-09-06 19:28:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: a895fddb71838ad96d93d25b18a86dac SHA-1: 1adae4953c26e391e6e777de06ca6b7895b42497 SHA-256: b83c6ed98a9c6997ec3b5d0a2c44f15ce85c2cbfd3bfeccecc98570466973438
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to various domains, many of which appear to be compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of external URI heuristics and link farm indicators further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://nomylo.ru/uplcv?utm_term=bosch+tassimo+fidelia+manual PDF link annotation
    • http://anhuishangbiao.com/upload_fck/file/2021-5-6/20210506095337872475.pdfIn PDF document text
    • http://tccsrl.org/userfiles/files/66116934744.pdfIn PDF document text
    • https://negaratoto.com/contents//files/53531748652.pdfIn PDF document text
    • https://baconbites.com/wp-content/plugins/super-forms/uploads/php/files/5laksa2997dncpvdsf9g84dsc0/35498189668.pdfIn PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/6a705f5a3ca901e28c9ec4d6ffb18f31/96991558786.pdfIn PDF document text
    • https://www.reflectionuk.com/wp-content/plugins/super-forms/uploads/php/files/5g040itmgf9glk62j0hrpondld/sagev.pdfIn PDF document text
    • http://ciarajewellery.com/editor_upload/file/fomobililubelukipiwabi.pdfIn PDF document text
    • http://gourmethousemacau.com/UploadFilesfile///85244909608.pdfIn PDF document text
    • https://ismart99.net/upload/files/48952046821.pdfIn PDF document text
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/f9a01e38a85729f74372519746eaa10c/60634976940.pdfIn PDF document text
    • http://xn----9sbbnbtte4cyg.xn--p1ai/ckfinder/userfiles/files/7365103048.pdfIn PDF document text
    • http://ebslang.net/_UploadFile/Images/file/40558526570.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/79301502642.pdfIn PDF document text
    • http://kashima.cc/userfiles/file/21443047585.pdfIn PDF document text
    • http://kabaretyimpresariat.pl/Upload/file/46139228023.pdfIn PDF document text
    • https://travelinnsuites.com/nbloom/fckuploads/file/fovenamipofi.pdfIn PDF document text
    • http://hrudolf.com/userfiles/pugetu.pdfIn PDF document text
    • https://nusantarabet4d1.com/contents//files/narenovivekokugeralalibem.pdfIn PDF document text
    • http://pvvc.cz/files/44131612772.pdfIn PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613246e1973e4---87422472106.pdfIn PDF document text
    • https://filetorme.com/upload/files/lemuderuzonovubofa.pdfIn PDF document text
    • http://ottotech.center/userfiles/file/37145482053.pdfIn PDF document text
    • https://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/j02ff3ck4neu11q1m5uokseq5p/pegojewit.pdfIn PDF document text
    • https://minhkygroup.com/luutru/files/63866049378.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/a60682ccfb3df911e40530fd8414a4cb/59473792164.pdfIn PDF document text
    • https://eingangrad.ch/userfiles/files/16803237206.pdfIn PDF document text
    • 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_off0000e565.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE565 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fd7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD7C 10792 bytes
SHA-256: b02a94ea6afd0de1ce82ea99ef89e55a38df85fb47b4f8866184c5c470a52661
font_02_sfnt_off00011633.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11633 17068 bytes
SHA-256: 911b4db8a3791f2105694a518257d90044554431fde626e356a5e3fa69104c16