Malicious PDF — malware analysis report

Static analysis result for SHA-256 da8427e394805304…

MALICIOUS

PDF

85.7 KB Created: 2021-09-19 08:19:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 8cb5934d7b3f528a23a32ca22d59f13c SHA-1: fa87013fa67b8ba46763818e9c977eba565e6282 SHA-256: da8427e394805304384161242167d902e5e14d09de9204c1c8c94b1296c8e409
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple external domains, many of which are hosted on compromised CMS uploads or disposable hosting. ClamAV and an ML classifier identified the file as malicious, specifically a phishing trojan. The embedded URLs suggest an attempt to redirect the user to malicious sites, likely for credential harvesting or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://cistenivytahu.cz/upload/file/ludobuwemafega.pdf In PDF document text
    • https://cjsc.se/ckfinder/userfiles/files/nuvovakebitogupitit.pdfIn PDF document text
    • https://vandolderskb.com/images/usr/wosowovemeva.pdfIn PDF document text
    • https://best-label.com/upload/files/masimavisivepurobum.pdfIn PDF document text
    • https://fmpride.com/wp-content/plugins/super-forms/uploads/php/files/d9658665a28e5a0b2f86110b92d8ead1/58946901148.pdfIn PDF document text
    • http://na3.it/misc/file/dimetufukur.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135dac688513---74823767853.pdfIn PDF document text
    • http://nirmalapublicschoolerumely.com/userfiles/file/50836197554.pdfIn PDF document text
    • https://mosconi.net/userfiles/file/2064744783.pdfIn PDF document text
    • https://theurbanthinktank.com/files/givof.pdfIn PDF document text
    • https://boucherienabli.com/uploads/FCK_files/file/jibalixinemevemamodosis.pdfIn PDF document text
    • http://mariondhuique-mayer.com/data/file/81028403021.pdfIn PDF document text
    • https://huuphongplastic.vn/uploads/images/files/39888725217.pdfIn PDF document text
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141b0f23b7bf---75091373530.pdfIn PDF document text
    • http://zxpgw.com/userfiles/file/jutirom.pdfIn PDF document text
    • http://kompletucetnictvi.cz/files/file/denatidokalasifuxojutuvef.pdfIn PDF document text
    • https://thietkeweblongan.com/upload/files/4951831470.pdfIn PDF document text
    • http://wecans.net/_UploadFile/Images/file/jekef.pdfIn PDF document text
    • http://louisamerino.com/userfiles/file/sususilatosexibu.pdfIn PDF document text
    • https://agronlogistics.com/userfiles/files/zilajigikujuni.pdfIn PDF document text
    • http://guojingmall.com/userfiles/file///38121824614.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/161357c4dba5fa---vimuvimeweto.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=free+up+system+storage+androidPDF 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_off0000e83b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE83B 18444 bytes
SHA-256: 222bebbf97e4debf563bdf14722f0223409b771ca604ec572b2bd683fd190fff
font_01_sfnt_off0001183e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1183E 10880 bytes
SHA-256: 152dfafdc0be2540b9c101784aeeda42363b49495749ba884817303798f7a48b
font_02_sfnt_off00013136.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13136 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1