Malicious PDF — malware analysis report

Static analysis result for SHA-256 bfc5f3a33c533abd…

MALICIOUS

PDF

81.8 KB Created: 2021-09-16 02:48:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 82435422a091677e77a3b2aa6fd49e83 SHA-1: 508e13296fdad2bb0b2bb4869e0c056c4d6e8a70 SHA-256: bfc5f3a33c533abdefa3b507bcf11421da2e013518673ff031249aff440073e5
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to PDF files hosted on various domains, suggesting a link farm or redirection mechanism. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic further supports this, indicating a pattern of using disposable hosting for multiple links. While no scripts were explicitly extracted, the nature of the embedded URLs and the overall detection suggest a phishing or malware distribution attempt, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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
  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://mqskin.com/luutru/files/23659834135.pdf In PDF document text
    • https://408of53crownstreet.com/assets/media/files/toxifigirowoxawe.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/161399570dcbf6---38357265431.pdfIn PDF document text
    • https://zweefvlieg.net/userfiles/file/56941000274.pdfIn PDF document text
    • http://terwaarde.be/ckfinder/userfiles/files/woxetar.pdfIn PDF document text
    • http://career-id.org/ckfinder/userfiles/files/tugexajuxejenuvaxiwava.pdfIn PDF document text
    • http://pwmtqatar.net/userfiles/file/rifababaritiba.pdfIn PDF document text
    • http://www.yoko-ono.be/images/userfiles/file/8261920864.pdfIn PDF document text
    • http://www.jucadent.es/ckfinder/userfiles/files/34189034456.pdfIn PDF document text
    • http://ebus.cn/up_file/file/21210999301.pdfIn PDF document text
    • https://signatureshreyas.in/userfiles/file/gezifaxere.pdfIn PDF document text
    • https://sandp-engineering.com/ckfinder/userfiles/files/32514923015.pdfIn PDF document text
    • http://chinalabware.es/d/files/54640174818.pdfIn PDF document text
    • https://suativisamsungtaihanoi.net/upload/files/28973214986.pdfIn PDF document text
    • http://rlponder.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/pozununugumafagagop.pdfIn PDF document text
    • https://granitabrasive.ro/editor_up/89567866556.pdfIn PDF document text
    • http://rutka.pl/media/upload/files/97d470ecc0c6e5b66fdde76dd6a1214a.pdfIn PDF document text
    • https://12shio2.com/contents/files/30925258459.pdfIn PDF document text
    • http://ildongwire.com/userfiles/file/87988613654.pdfIn PDF document text
    • https://lexcyberia.com/userfiles/files/66292870111.pdfIn PDF document text
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613258cdc9d54---kikutopinuberarute.pdfIn PDF document text
    • http://27derajat.com/assets/ckfinder/core/connector/php/uploads/files/wizinamugupazegi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=expo+iphone+qr+codePDF link annotation
    • https://cakamuzejs.riga.lv/ckfinder/userfiles/files/95541777259.pdfIn PDF document text
    • 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_off0000dc4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC4A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f461.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF461 10368 bytes
SHA-256: a331423abc04383649b66ffa38536e5b8c6ef95775ca0c4422781a2f952d6c64
font_02_sfnt_off00010b6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B6C 17664 bytes
SHA-256: da7b0e6e6f2928817e828ff26145ce8c91b9084397749b458b0fc0bcae3be063