Malicious PDF — malware analysis report

Static analysis result for SHA-256 81133890a50107e7…

MALICIOUS

PDF

45.7 KB Created: 2020-08-31 22:18:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 371d0f001a27938c85958d8cef266fd6 SHA-1: 55c0e43d5593ef4ff77a59a9bc1f1bade9184ec6 SHA-256: 81133890a50107e748ba6dfa60ab33fdfded4c06e5f442159fe05e56b467833a
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a heuristic firing for linking to known malicious redirector infrastructure, specifically 'https://ttraff.cc/wix?keyword=crossword+jigsaw+answers+nature+1'. It also exhibits characteristics of a PDF link farm, embedding a large number of external PDF links, with 'https://cdn.shopify.com/s/files/1/0437/5016/2583/files/libro_balun_canan_gratis.pdf' being one of the first identified. The ML classifier strongly flagged this PDF as malicious, indicating a high probability 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/wix?keyword=crossword+jigsaw+answers+nature+1
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0437/5016/2583/files/libro_balun_canan_gratis.pdf
    • https://cdn.shopify.com/s/files/1/0428/0962/2691/files/15194814378.pdf
    • https://cdn.shopify.com/s/files/1/0435/0076/5336/files/21412099678.pdf
    • https://cdn.shopify.com/s/files/1/0429/2686/6599/files/xixaruvosunimiga.pdf
    • https://static.usrfiles.com/ugd/38bf1f_97234c5fc84843bd8e7f48100ebbbaab.pdf
    • https://static.usrfiles.com/ugd/fb5067_c068cf2240524cbb8bed75370cfd6dc1.pdf
    • https://static.usrfiles.com/ugd/b8c837_24929345fbb940dbb2dee78f07c4ccf0.pdf
    • https://static.usrfiles.com/ugd/ca9b0a_86a73a655e504edcae02d50f2b06d2fc.pdf
    • https://cdn.shopify.com/s/files/1/0432/2358/0830/files/53764730929.pdf
    • https://cdn.shopify.com/s/files/1/0433/2827/4585/files/32209079392.pdf
    • https://cdn.shopify.com/s/files/1/0433/8204/6869/files/harley_davidson_6.5_boombox_manual.pdf
    • https://cdn.shopify.com/s/files/1/0438/3303/2864/files/alexa_not_connecting_to_internet.pdf
    • https://cdn.shopify.com/s/files/1/0430/7773/0464/files/52160553435.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_off0000755c.bin
4f3578e82a71e1e26d12c5eec668196faaae418f318c67e7bf25aa8b67227257
pdf-font-stream PDF embedded font (sfnt) at offset 0x755C 5084 bytes
font_01_sfnt_off000086c7.bin
eced2c4c6a29b3bb20ed1d1bc94c920520a558d8de3fcfdb66d63a315d4cfad9
pdf-font-stream PDF embedded font (sfnt) at offset 0x86C7 10260 bytes