Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f555536b00b1ca5…

MALICIOUS

PDF

70.3 KB Created: 2021-09-23 01:13:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 4d3f715c2104f591b3497369202c7e11 SHA-1: 0d8208cc84f1a408afec83b7baf3d7c816cfbe28 SHA-256: 8f555536b00b1ca5d119b5f535d17eb0e8bf754e7e9a6fb44f88beb75c144199
94 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a phishing trojan by ClamAV. Static analysis revealed it functions as a link farm, containing numerous embedded URLs pointing to various domains. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a high number of distinct hosts and links per host, suggesting an attempt to manipulate search engine results or distribute malicious content through a large network of redirects. No scripts were extracted, but the overall structure and detection point to a malicious intent to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier suspicious score 0.4270

Heuristics 4

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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
  • 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.fyna.com.au/application/third_party/ckfinder/userfiles/files/14573018193.pdf In PDF document text
    • http://constantemails.com/userfiles/file/163229988475396346239.pdfIn PDF document text
    • http://www.perchegouet.com/ckfinder/userfiles/files/36403904724.pdfIn PDF document text
    • http://danieldesignpro.com/userfiles/21881007634.pdfIn PDF document text
    • https://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/80b841876b4210af48131c0b32dfeb05/tilipekebofewe.pdfIn PDF document text
    • http://promocode.lu/userfiles/files/89855856546.pdfIn PDF document text
    • http://biolabsrl.org/userfiles/files/78857980707.pdfIn PDF document text
    • https://cupanghitam.com/contents/files/nozufawe.pdfIn PDF document text
    • https://www.ccs-corporation.com/ckfinder/userfiles/files/nesafiwamogurepivedinizo.pdfIn PDF document text
    • https://giant-nano.com/app/webroot/userfiles/files/73641031489.pdfIn PDF document text
    • https://triptoboloyfoundation.org/editorsfiles/files/bojiwirifow.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1613f42f8960e3---telokalopuwudebuwanixeron.pdfIn PDF document text
    • https://abzesolar.com/uploads/files/33699394306.pdfIn PDF document text
    • http://denis-lefebvre-services.com/fichiers/file/45644310326.pdfIn PDF document text
    • http://trubaopt.ru/content/file/45594579423.pdfIn PDF document text
    • http://stellar-toys.com/ckfinder/userfiles/files/gamanibasapijese.pdfIn PDF document text
    • http://floridadressyourhome.com/uploaded_files/userfiles/files/zoxozadolepemafesilubupiv.pdfIn PDF document text
    • https://www.highlandernepal.com/assets/ckfinder/userfiles/files/mezanesusenepirevaxet.pdfIn PDF document text
    • http://huonglonghotel.com/uploads/image/files/51085991753.pdfIn PDF document text
    • http://hawaiisushi.iorderfoods.com/uploads/files/46480806703.pdfIn PDF document text
    • http://globalfeedindustry.com/upload/files/nipalexujujekuxitenusuv.pdfIn PDF document text
    • https://keluargamimpi.com/contents/files/3399697417.pdfIn PDF document text
    • http://home-plast.ru/foto/files/56302017723.pdfIn PDF document text
    • https://wemservice.com/ckfinder/userfiles/files/rivarisota.pdfIn PDF document text
    • http://hidramaco.com/files/files/91458890119.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=best+android+apps+for+small+businessPDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cbd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBD3 10952 bytes
SHA-256: 8e4d08e571cfbdb49f46ef45149c3abd69f6e183b4fd857f6f9588be29d699f5
font_01_sfnt_off0000e4f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4F5 16576 bytes
SHA-256: fc9e6db0345f185f43469f2456554490e6971eacc1c03ac43baaf515b74232d1