Malicious PDF — malware analysis report

Static analysis result for SHA-256 de4888847881c0c5…

MALICIOUS

PDF

40.9 KB Created: 2020-08-31 11:31:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2e12979d549c190007a708d0dce09621 SHA-1: ed2fc1b6f6edb87629267f807607305b206979cc SHA-256: de4888847881c0c5b2ff45555a12f9529831641ddf09f8e77966a83237a4aba8
152 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded links, with one specifically pointing to a known malicious redirector. The ML classifier also strongly indicated maliciousness. The document body, though heavily obfuscated, contains the URL that triggered the malicious redirector heuristic, suggesting an attempt to lure users to malicious content.

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=ejercicios+perifrasis+verbales+3+eso
    • https://static.usrfiles.com/ugd/b8c837_c8c9b2be1bce47338e111739fe604b0b.pdf
    • https://static.usrfiles.com/ugd/0dcf4b_c6ac4ae70be640dca7909a71c0646c2c.pdf
    • https://static.usrfiles.com/ugd/f65175_10eeb3fcf50e4b52a3311a80fb716ad2.pdf
    • https://static.usrfiles.com/ugd/b916f4_8816706ef4474d11a0fc571ea8d9055e.pdf
    • https://static.usrfiles.com/ugd/a31856_9a61e1dccee64ddfa23eeebb4a889f9a.pdf
    • https://cdn.shopify.com/s/files/1/0431/6708/8800/files/education_responsive_web_templates_free.pdf
    • https://cdn.shopify.com/s/files/1/0437/4305/1937/files/epistemology_definition_philosophy.pdf
    • https://cdn.shopify.com/s/files/1/0429/5586/6263/files/53813987546.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/72438278193.pdf
    • https://cdn.shopify.com/s/files/1/0433/0989/1742/files/77892107898.pdf
    • https://cdn.shopify.com/s/files/1/0432/3701/5719/files/9543083454.pdf
    • https://cdn.shopify.com/s/files/1/0434/4047/2229/files/vatogutisoxigo.pdf
    • https://cdn.shopify.com/s/files/1/0434/2326/9014/files/runescape_fletching_guide.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_off00005f34.bin
679fbc1beca959800b0f6c2f1efbc664f2eda0fe1919224193e7255b578f0cb6
pdf-font-stream PDF embedded font (sfnt) at offset 0x5F34 5404 bytes
font_01_sfnt_off000071af.bin
1dc0872d56962b8c9ede39b9e2762873f6c635a89e223c73ae0d3c41c8d47093
pdf-font-stream PDF embedded font (sfnt) at offset 0x71AF 10964 bytes