Malicious PDF — malware analysis report

Static analysis result for SHA-256 09db17ba95bd73d9…

MALICIOUS

PDF

31.8 KB Created: 2020-08-22 13:46:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 038a5076942972c80153ec910f7cb2ba SHA-1: 599ebde3f640f387dc94a46c1760a8c02017e4ec SHA-256: 09db17ba95bd73d9ec5ab498f5898e334a1cb2d804c89c12e982da31bbab7fed
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of embedded links, many of which point to external sites, indicating a link farm or SEO spamming attempt. One of the primary links directs to a known malicious redirector, 'ttraff.ru', disguised as a 'past tense worksheet'. The ML classifier also strongly flagged this PDF as malicious. No scripts were extracted, but the presence of numerous links suggests an attempt to drive traffic to malicious infrastructure.

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/pify?keyword=past+tense+worksheet+ks2
    • http://files.texasumbra.org/uploads/1/3/1/4/131453114/zevuw_kuzojusisikife_wewekovisu.pdf
    • http://belen.createdragons.com/uploads/1/3/1/3/131383652/lavomilijivo_golufi.pdf
    • http://files.vycareer.org/uploads/1/3/0/8/130874524/lixege.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0427/7708/4070/files/juraponifofopajix.pdf
    • https://cdn.shopify.com/s/files/1/0436/1384/7714/files/1389717929.pdf
    • https://cdn.shopify.com/s/files/1/0437/4944/1688/files/85670180036.pdf
    • https://cdn.shopify.com/s/files/1/0434/5364/4966/files/understanding_basic_statistics_5th_edition.pdf
    • https://cdn.shopify.com/s/files/1/0433/5036/0232/files/85525673140.pdf
    • https://cdn.shopify.com/s/files/1/0459/9962/0263/files/18842718064.pdf
    • https://cdn.shopify.com/s/files/1/0427/6623/7852/files/lujinozuv.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00004064.bin
94e170d188ea65e8f33c38c451398653698813bfb7b68cbf2f7b37167c741bd0
pdf-font-stream PDF embedded font (sfnt) at offset 0x4064 5028 bytes
font_01_sfnt_off00005187.bin
f1165a55d3be822ecf118bd05dbf3d519f548a1e4e8c9b4f4e21d031450219f9
pdf-font-stream PDF embedded font (sfnt) at offset 0x5187 9848 bytes