Malicious PDF — malware analysis report

Static analysis result for SHA-256 2157bc3cd68aecf4…

MALICIOUS

PDF

78.0 KB Created: 2021-09-19 08:03:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: f5cda5fa5486e573eb1d50a971d334d6 SHA-1: d26f164238ddd93e7c493fc83548377ba24d2f11 SHA-256: 2157bc3cd68aecf467e24a8b167dc6d27f5e039829c06d96024d3176a6be5cf6
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as a phishing trojan. It contains numerous embedded URLs, many of which are part of a link farm hosted on disposable domains, indicating a phishing or malware distribution attempt. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9899

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://krisoc.ru/uplcv?utm_term=mortal+kombat+movies+2020 PDF link annotation
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130903b72464---95859090603.pdfIn PDF document text
    • http://105chers.netsociality.com/upload/files/kirokugaweg.pdfIn PDF document text
    • http://otvorene-srdce.sk/userfiles/file/sesugutozebudemegit.pdfIn PDF document text
    • https://jooli.ru/ckfinder/userfiles/files/tijiwiduwafeguk.pdfIn PDF document text
    • https://drosamahetta.com/userfiles/file/20526780667.pdfIn PDF document text
    • http://locthanhroyal.com/upload/files/74350135806.pdfIn PDF document text
    • http://tcsklife.com/filespath/files/20210905102328.pdfIn PDF document text
    • http://umffz21.ru/admin/ckfinder/userfiles/files/3527148772.pdfIn PDF document text
    • https://dortmundpools.com/contents/files/zunobamokenixibot.pdfIn PDF document text
    • http://baobianhkhang.com/upload/files/wiraruvikawosorerupobula.pdfIn PDF document text
    • http://liderzy.natura2000.pl/imgturysta/files/99212258989.pdfIn PDF document text
    • http://lejuriste.ru/files/file/50325795687.pdfIn PDF document text
    • http://stuarteisbrucklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/12107549964.pdfIn PDF document text
    • https://www.sudoku-cool.com/ckfinder/userfiles/files/32717203119.pdfIn PDF document text
    • http://hhsmelt.com/upload/files/23257381665.pdfIn PDF document text
    • https://saleskerala.com/ckfinder/userfiles/files/konukizidirisulu.pdfIn PDF document text
    • http://hyundaidongdo3s.com/images/files/74872066583.pdfIn PDF document text
    • https://grandhotelushba.com/userfiles/file/59695446894.pdfIn PDF document text
    • http://genarchi.com/data/temp/file/31616693336.pdfIn PDF document text
    • http://originalavto.ru/userfiles/file/rizisugejobaxilaji.pdfIn PDF document text
    • http://jindi2010.com/uploadfile/files/55213152978.pdfIn PDF document text
    • https://client-sms.com/ckfinder/userfiles/files/tusawedoxisutikis.pdfIn PDF document text
    • http://spbmedax.ru/sites/default/files/uploads/9949661895.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/pubemaxejelajiw.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/161426a4386bf1---29875704176.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_off0000cd1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD1B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e52d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE52D 17448 bytes
SHA-256: 34ffbb57d7ea6cbbdab1f6ce0f97c1ba51090015e38fca7ff616dbc4a238ba1e
font_02_sfnt_off00011238.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11238 10696 bytes
SHA-256: e5265f7d074bf8e2e8d344570a6e4542e320e3a6e0120b3c96b48a0d2fd0090e