Malicious PDF — malware analysis report

Static analysis result for SHA-256 c250db2ec8bc755d…

MALICIOUS

PDF

38.3 KB Created: 2020-08-09 01:19:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0b69eacb1f0c89806308798bca370f43 SHA-1: 63c24d34106a0ab01fa9ac7089846b45769ce4da SHA-256: c250db2ec8bc755d8024e2634a74836605fa6278992cb87c3a799d81b5c2586d
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell T1204.002 Malicious Link

The PDF contains a link farm and a critical redirector link pointing to ttraff.ru, which is known malicious infrastructure. The document body, though corrupted, contains the text 'Demonstrative pronouns exercises pdf with answers' and the malicious URL, suggesting a lure to trick users into clicking the link. The ML classifier strongly flagged this PDF as malicious. No scripts were extracted from this sample.

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=demonstrative+pronouns+exercises+pdf+with+answers
    • http://files.bemedialiterate.com/uploads/1/3/0/7/130775665/pudisase.pdf
    • http://files.markcreative.ca/uploads/1/3/0/7/130775936/8e7d7af.pdf
    • http://tixokage.breadolives.com/uploads/1/3/0/8/130874038/pixukipa.pdf
    • http://files.helenmccreery.com/uploads/1/3/1/1/131163959/fapevatejik_viwowazekuze_fimase_wunapalov.pdf
    • https://cdn.shopify.com/s/files/1/0434/1104/6558/files/bncc_resumo.pdf
    • https://cdn.shopify.com/s/files/1/0433/7614/8638/files/gejizux.pdf
    • https://cdn.shopify.com/s/files/1/0429/0609/1687/files/pusafadumefukavajaj.pdf
    • https://cdn.shopify.com/s/files/1/0435/6145/1681/files/82275113362.pdf
    • https://cdn.shopify.com/s/files/1/0431/7439/6065/files/java_applet_tutorial_w3schools.pdf
    • https://cdn.shopify.com/s/files/1/0431/2930/7296/files/petepanemubo.pdf
    • https://cdn.shopify.com/s/files/1/0433/6363/1272/files/wubisisaxaxobenijokeg.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/86662201832.pdf
    • https://cdn.shopify.com/s/files/1/0440/5238/1846/files/66686656740.pdf
    • https://cdn.shopify.com/s/files/1/0430/8546/3713/files/dumixinal.pdf
    • https://cdn.shopify.com/s/files/1/0431/6761/3087/files/pitobatinob.pdf
    • https://cdn.shopify.com/s/files/1/0438/3080/4637/files/zaguruluwibagomevirutove.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_off000056e2.bin
bb65323bc5e912f05f6a8486b54c788240000a69e32d3bcf42141b66f53196f5
pdf-font-stream PDF embedded font (sfnt) at offset 0x56E2 5584 bytes
font_01_sfnt_off000069d3.bin
76a5ea5de8680657e21dca153f19869be46d24643544f4c9a891efd7ea583f5b
pdf-font-stream PDF embedded font (sfnt) at offset 0x69D3 10036 bytes