Malicious PDF — malware analysis report

Static analysis result for SHA-256 6e4b81a50f9a1fa7…

MALICIOUS

PDF

39.6 KB Created: 2020-08-30 12:05:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 7ce029624d6c6e8a4df07d1f93b3c699 SHA-1: 48cc68943fd69af1789b08c9b865c9be59dfa149 SHA-256: 6e4b81a50f9a1fa7676891fadee7776e70ebaff8a61c878c6dfaae4f5c60a427
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded links, many of which point to external PDF files, suggesting a link farm or SEO spamming attempt. One of the primary links, https://ttraff.ru/wix?keyword=libro+fisica+general+hector+perez+montiel+5ta+edicion, is flagged as a malicious redirector. The ML classifier also strongly indicated maliciousness. The document body contains garbled text but includes the malicious URL, reinforcing the lure.

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/wix?keyword=libro+fisica+general+hector+perez+montiel+5ta+edicion
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/10e3af_e9059f5789674d44b2597f0758bf5440.pdf
    • https://static.usrfiles.com/ugd/b8c837_9dd735709d854609871dd0341f59683b.pdf
    • https://static.usrfiles.com/ugd/b8c837_ec1581671e9f4cbabdd2bf6ea3278440.pdf
    • https://static.usrfiles.com/ugd/5bb01c_c81eca78699547dea776525015daa82e.pdf
    • https://cdn.shopify.com/s/files/1/0431/9513/8208/files/49310959102.pdf
    • https://static.usrfiles.com/ugd/b8c837_cff675cc254f44c1bde6a67e3e295c02.pdf
    • https://static.usrfiles.com/ugd/10e3af_ab0ab59db0654023be5a66b07468569c.pdf
    • https://static.usrfiles.com/ugd/e3c460_d7102cc6ce2e40e69829c95bb236a62b.pdf
    • https://cdn.shopify.com/s/files/1/0437/4455/9258/files/avengers_endgame_soundtrack_portals.pdf
    • https://cdn.shopify.com/s/files/1/0438/9175/3115/files/adjetivos_comparativos_em_ingles.pdf
    • https://cdn.shopify.com/s/files/1/0437/2063/8632/files/denovawetitutexazira.pdf
    • https://cdn.shopify.com/s/files/1/0432/2502/2621/files/gipafi.pdf
    • https://cdn.shopify.com/s/files/1/0432/0709/8529/files/accountancy_comprehensive_project_for_class_12.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_off000056e5.bin
68cb61ad603af6ae3dbe1380d4e73253f53b3bd412b055e4e32dbcd870d38be2
pdf-font-stream PDF embedded font (sfnt) at offset 0x56E5 5824 bytes
font_01_sfnt_off00006a88.bin
a52fb6c4a2a9fa246df1cad32016eb95b80ea709a88e1a0094edf569f08a63df
pdf-font-stream PDF embedded font (sfnt) at offset 0x6A88 11644 bytes