Malicious PDF — malware analysis report

Static analysis result for SHA-256 21fd79ddeea25d6c…

MALICIOUS

PDF

73.6 KB Created: 2021-09-09 13:43:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 549a153b43021c42b7a179979517d1d1 SHA-1: 2f6c55f0bad8e3e38a8ccc2cb2a309e25f9cf870 SHA-256: 21fd79ddeea25d6c258e6aad3e6d1df5c913bf7a535d8135fca0020f9ce9e0b5
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous embedded URLs, many of which are hosted on disposable domains, indicating a link farm designed to redirect users to potentially malicious content. The heuristic 'SE_LOLBIN_RUN_COMMAND' suggests the document may attempt to execute commands, likely to download and execute further payloads.

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
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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://www.cdsale.org.au/application/third_party/ckfinder/userfiles/files/raxaxipuniz.pdf In PDF document text
    • https://krossi.ru/images/content/files/sitomitojipumodekidabonid.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/16d7411e40af1060c68b86b904c4c08e/8964378042.pdfIn PDF document text
    • http://bajcsidavidfoto.com/_user/file/48644529389.pdfIn PDF document text
    • https://www.lamuccacompany.com/wp-content/plugins/super-forms/uploads/php/files/e63462b887b999922063973a880f28b0/64130984147.pdfIn PDF document text
    • http://wolfroccatiassociati.it/userfiles/files/26102308329.pdfIn PDF document text
    • https://hoya.hr/UserFiles/file/42552081560.pdfIn PDF document text
    • http://charmingcurls.se/upload/file/kasixuzakinanigiv.pdfIn PDF document text
    • http://ciccioinpentola.com/userfiles/files/pipuga.pdfIn PDF document text
    • http://vektor28.ru/userfiles/file/fatugifede.pdfIn macro / runtime command snippet
    • http://4bx.pl/public/file/35130841941.pdfIn macro / runtime command snippet
    • http://hakanhurdacilik.com/userfiles/file/wetomawixade.pdfIn PDF document text
    • http://whuntex.ru/userfiles/file/wepipujotovumesevawoxuva.pdfIn PDF document text
    • http://longarmquiltacademy.com/fckeditor/userfiles/file/dapaguziwusutuxoluki.pdfIn PDF document text
    • http://konsultacjenaukowe.eu/Upload/file/wavijulerasajisipoje.pdfIn PDF document text
    • http://lmleadmanagement.com/userfiles/files/54705782100.pdfIn PDF document text
    • http://boracayg.com/FileData/ckfinder/files/20210904_9B3BDA9C21BF574F.pdfIn PDF document text
    • http://w-w.cn/isee/pfm/cms/uploadfile/fck/file/wofar.pdfIn PDF document text
    • https://maryamghiasi.com/images/upload/files/jodesukiranulilir.pdfIn PDF document text
    • http://3sdent.com/upload/files/26073994255.pdfIn PDF document text
    • http://el-system.jp/uploads/2012/files/linuvunotugesa.pdfIn PDF document text
    • http://ciccioinpeIn macro / runtime command snippet
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=english+short+stories+for+advanced+learners+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_off0000be70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE70 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d687.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD687 10948 bytes
SHA-256: c5e50b3fc637c3c8183c68194f53b8656a03bdd9933be14de7f3160a5d6d8199
font_02_sfnt_off0000efa4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFA4 16108 bytes
SHA-256: df439302767fbf04217a742a538fa5095cbf054049ff744f76645fbffc908d91