Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d20b94263703c1f…

MALICIOUS

PDF

41.5 KB Created: 2020-07-09 03:57:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2477a908af7a58124506376ba81af05e SHA-1: 7b1704727bd1c2508170d80316dd25610bdd6015 SHA-256: 8d20b94263703c1fca77be3faa519e87f972f4a026edfe27ed3d95d2600b0100
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF document contains a large number of embedded URLs, many of which point to link farms designed for SEO manipulation. One critical heuristic identified a link to a known malicious redirector at https://ttraff.ru/wb?keyword=engineering%20drawing%20objective%20type%20questions%20and%20answers%20pdf%20free%20download. The document body also contains this URL and other links to PDF files, suggesting a lure to download potentially malicious content. The ML classifier strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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 https://ttraff.ru/wb?keyword=engineering%20drawing%20objective%20type%20questions%20and%20answers%20pdf%20free%20download
    • http://files.pofwc.org/uploads/1/3/0/7/130775856/tuwubagat-zebikefolas-lobirume-vokajoj.pdf
    • http://files.kafyeblaan.com/uploads/1/3/1/8/131856381/becb5.pdf
    • http://files.carolynmartinodesign.com/uploads/1/3/1/4/131453648/kesewepevoderu-xopokebisuvatix.pdf
    • http://files.elliot-design.co.uk/uploads/1/3/1/4/131438629/zamog.pdf
    • http://files.rountos.com/uploads/1/3/1/8/131856293/f104a2da30bcc1b.pdf
    • http://files.changingfutures.org.uk/uploads/1/3/1/6/131606087/mufegesitawiko-matuwomap-xivekun-vokozufeletefuz.pdf
    • https://varaziwatu.files.wordpress.com/2020/07/63552696729.pdf
    • https://zezonog.files.wordpress.com/2020/07/loralumenoponog.pdf
    • https://zigadapojunu.files.wordpress.com/2020/06/32400566225.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/telisupuf.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/51220099535.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/womosoravitixugefiwil.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/mozesuseb.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005be8.bin
09c105a265edd48c10c83ac154b64c7d6787eb0e4f7b62495df905ac42aae286
pdf-font-stream PDF embedded font (sfnt) at offset 0x5BE8 5760 bytes
font_01_sfnt_off00006f9f.bin
6ebeea90f01fd89e1e54d8051c95f42342ed9d4638c5dcbe464766939cf0212c
pdf-font-stream PDF embedded font (sfnt) at offset 0x6F9F 12796 bytes