Malicious PDF — malware analysis report

Static analysis result for SHA-256 83ef1fd2e4be496f…

MALICIOUS

PDF

86.0 KB Created: 2021-08-14 04:53:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a4827120b13ca6f55f47acd146a40694 SHA-1: eb88c3d5d0609734c6c099483ce347081de2afba SHA-256: 83ef1fd2e4be496f08352f854167f08e54b7d954d87ba42710babc016a9946b0
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting an attempt to distribute further malicious content or phish users. The presence of multiple external URIs and a link farm heuristic strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9219

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://ourdesign.hk/ckfinder/userfiles/files/tipawulufukilasodurepipe.pdf In PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/b5ddc03cc91764f2fe1ed4e9f81a24c5/fajujeturirutirep.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d2028bc19c---zabagujepozozazigalaw.pdfIn PDF document text
    • http://rajskiewakacje.pl/userfiles/file/makonaxadulerirafupatu.pdfIn PDF document text
    • http://esoftland.com/userfiles/file/54408077156.pdfIn PDF document text
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/7e7205a87af42e39cb02bcaecfaadfac/20273790534.pdfIn PDF document text
    • http://bookblog.kr/data/file//files/89032558737.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7bfef6f35c---relinevefizajuko.pdfIn PDF document text
    • https://angkorphotographyguide.com/userfiles/file/64752694921.pdfIn PDF document text
    • https://people11people.gr/uploads/File/wuvizojopadin.pdfIn PDF document text
    • https://girilawfirm.com/content_files/files/vilufabarosexalu.pdfIn PDF document text
    • http://rasciindia.com/firetech/ckupload/files/37990975874.pdfIn PDF document text
    • http://summithigh75.com/clients/867147/File/51616256134.pdfIn PDF document text
    • http://stmrcstvm.com/userfiles/file/14782546111.pdfIn PDF document text
    • https://trellisdundee.com/wp-content/plugins/super-forms/uploads/php/files/e87c1aa25173178d5d01f8240f0f30b4/35687003832.pdfIn PDF document text
    • https://preprodpcb.com/userfiles/files/78273019074.pdfIn PDF document text
    • https://thegioibaobicarton.com/Images_upload/files/jetifipa.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075be601a11a---rivewigo.pdfIn PDF document text
    • http://thamdinhgiadaiquang.com/img/files/71374321725.pdfIn PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/46b333edb14d8e2c0e56a61b8d7f659c/newosajivoxefudat.pdfIn PDF document text
    • http://artechq8.com/beta/uploads/files/98203253581.pdfIn PDF document text
    • http://www.atrium-tuiles.com/wp-content/plugins/formcraft/file-upload/server/content/files/160875e41f0433---26171613998.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=telugu+movies+hd+mobile+download+2019PDF 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_off0000f89f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF89F 11316 bytes
SHA-256: 2b13badb4b2ae2ca1771ed4f650ca4e95746e563e6b3eba7e81826734114b056
font_01_sfnt_off000112e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112E6 17608 bytes
SHA-256: faf31debfe55eaeabf9ef2aab7360d0cd4232f704937ab18c8bd2461ee543548
font_02_sfnt_off0001406b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1406B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1