Malicious PDF — malware analysis report

Static analysis result for SHA-256 9f38eb35bcc27651…

MALICIOUS

PDF

38.2 KB Created: 2020-08-19 15:42:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e921c1e0f7f04849f14819f29047cf41 SHA-1: c24c6bec2c6c84242d52eddcfd8b9e17b6165cad SHA-256: 9f38eb35bcc27651759eef0c2e4e8ca907e619220675c6bb45a81b20b08c8b2a
154 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for a malicious redirector link, which is also present in the document body. The ML classifier strongly indicates maliciousness. The document appears to be a lure, disguised as a piano sheet music PDF, to entice users to click on the malicious URL. The presence of numerous Shopify URLs suggests an attempt to blend in with benign content, but the primary redirector is the key indicator of malicious intent.

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.cc/pify?keyword=trisha%2527+s+lullaby+piano+sheet+pdf
    • http://files.kathybernat.com/uploads/1/3/0/7/130776409/3062255.pdf
    • https://cdn.shopify.com/s/files/1/0432/5038/5051/files/gowenarijigaxusabe.pdf
    • https://cdn.shopify.com/s/files/1/0433/4059/5352/files/anyone_someone_anybody_somebody_everybody_everybody.pdf
    • https://cdn.shopify.com/s/files/1/0440/2606/9157/files/9945374741.pdf
    • https://cdn.shopify.com/s/files/1/0435/4749/2506/files/sesoxogumap.pdf
    • https://cdn.shopify.com/s/files/1/0434/6370/4729/files/tatopurejasos.pdf
    • https://cdn.shopify.com/s/files/1/0435/8176/7841/files/berserk_volume_22.pdf
    • https://cdn.shopify.com/s/files/1/0428/0729/6163/files/jetutosaregizezize.pdf
    • https://cdn.shopify.com/s/files/1/0433/5144/1560/files/98904595548.pdf
    • https://cdn.shopify.com/s/files/1/0436/4143/8366/files/68539556334.pdf
    • https://cdn.shopify.com/s/files/1/0430/8851/1125/files/60588112339.pdf
    • https://cdn.shopify.com/s/files/1/0428/6355/8815/files/semexuxobusuxokamexixefil.pdf
    • https://cdn.shopify.com/s/files/1/0428/3380/5471/files/tafunejinanororelujifised.pdf
    • https://cdn.shopify.com/s/files/1/0431/2861/9168/files/88445340986.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_off000049fd.bin
c0f0f1403b78ccf81b751b8261bfb63012751f5b4e9028f905ca483732722362
pdf-font-stream PDF embedded font (sfnt) at offset 0x49FD 5352 bytes
font_01_sfnt_off00005c31.bin
836e1dca3e372a045d89b46b7bd4bb21e65cec7b3c637460813e01393cadc682
pdf-font-stream PDF embedded font (sfnt) at offset 0x5C31 14656 bytes