Malicious PDF — malware analysis report

Static analysis result for SHA-256 84b3c83dc306daea…

MALICIOUS

PDF

81.1 KB Created: 2021-10-05 13:45:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 041bec8de25e15e70b08b8df17a36280 SHA-1: 84973ae35ca76b8fde89f43eedc1bf3e52a0fa44 SHA-256: 84b3c83dc306daea3236a4fc7f6c1a2f21ed5cf698bdfd7e99a889d08822ef30
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file is a PDF containing numerous links to external websites, many of which are hosted on compromised CMS platforms or appear to be disposable. The ClamAV detection and the heuristic findings indicate a phishing or malicious link distribution scheme. The document body is heavily obfuscated and does not provide direct user-facing content, suggesting its primary purpose is to host these links.

Machine Learning

  • Nyx PDF Classifier clean score 0.2122

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://www.sczct.com/up_files/file/gadojaxili.pdf In PDF document text
    • http://www.c-l-r-p.com/admin/ckfinder/userfiles/files/bavagenoboloxeboja.pdfIn PDF document text
    • https://candbco.com/ckfinder/userfiles/files/dinibemukijoxirilipu.pdfIn PDF document text
    • http://oryginalnedekoracje.pl/userfiles/file/43850144361.pdfIn PDF document text
    • http://www.prodomasa.com/ckfinder/userfiles/files/81739975888.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/17722084958.pdfIn PDF document text
    • https://myoffice.strategygroupglobal.com/uploads/files/12400612304.pdfIn PDF document text
    • https://korvioinfotech.com/ckfinder/userfiles/files/43538332662.pdfIn PDF document text
    • https://self-storage.sg/images/uploadedimages/file/zikitenugowesaweke.pdfIn PDF document text
    • http://membranekeyboard.pl/_data/file/64323384429.pdfIn PDF document text
    • http://muacuoi.vn/Pictures/files/25540151078.pdfIn PDF document text
    • http://xn-----elcksuhhemsi4e.xn--p1ai/files/files/49437184797.pdfIn PDF document text
    • http://formacio.fic.cat/uploads/file/90628903873.pdfIn PDF document text
    • https://elitteaccesorios.com/wp-content/plugins/super-forms/uploads/php/files/010a1ural8kgnj9gf0l9gj3nqf/32938991397.pdfIn PDF document text
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147de3336156---relevikelivevoke.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/766a403cd0d7ef1f1414c6c0bf6f39ed/lokolodatej.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614d843d43e8d---97340257076.pdfIn PDF document text
    • http://www.fashiongale.ro/userfiles/files/76850138689.pdfIn PDF document text
    • http://poketomecam.com/uploads/files/58791442411.pdfIn PDF document text
    • https://ryokanclub.com/FileData/ckfinder/files/20210910_D43C5CAF1D52C470.pdfIn PDF document text
    • http://gasasosong.com/upload/fckeditor/file/luwesewonesedekatigexared.pdfIn PDF document text
    • http://betonkeritesek.eu/Content/files/vebuvukegib.pdfIn PDF document text
    • http://nachhilfeschule.havonix.com/ckfinder/userfiles/files/xozobozarogunafa.pdfIn PDF document text
    • http://rayanchem.com/d/files/denetazusonesararukoxo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=old+fashioned+mince+beef+piePDF link annotation
    • 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_off0000dd2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD2D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f53f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF53F 19524 bytes
SHA-256: 39533398fc78fd8397ace78edf7566e07e42c871d62d07ff5fec2f59736000ce
font_02_sfnt_off0001282b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1282B 10852 bytes
SHA-256: 0b8ef507da7548a5811b566ac731013f28d2378630d8d891190e0160d995f98e