Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1b4a4ff27dba4fe…

MALICIOUS

PDF

47.2 KB Created: 2020-08-29 22:43:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 10889218993ce0a6d50bc17ffb8ffee1 SHA-1: 413f4970831044137d49af2cd9531c54c8667708 SHA-256: b1b4a4ff27dba4fe3b2474a23ba14da62d41104b65e203c006f019c808b6ebb5
152 Risk Score

Malware Insights

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

The PDF contains a mass of external links, many of which point to a known malicious redirector. The document body, though heavily corrupted, contains text related to 'exercícios resolvidos sobre movimento circular uniforme' and the malicious URL, suggesting a lure to trick users into clicking the malicious link. The ML classifier also strongly indicated maliciousness.

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.me/wix?keyword=exerc%25C3%25ADcios+resolvidos+sobre+movimento+circular+uniforme
    • https://static.usrfiles.com/ugd/9b33c5_5e18b705a82d426c94080cfd4ae09a1e.pdf
    • https://static.usrfiles.com/ugd/b8c837_708fe6c2d1b544dd839c8f4c871f41a5.pdf
    • https://static.usrfiles.com/ugd/b8c837_2340e696f5dc42019d3008791caf6d4b.pdf
    • https://static.usrfiles.com/ugd/c836c3_89e3688007a144e289ec1010f9687ed3.pdf
    • https://cdn.shopify.com/s/files/1/0427/9320/5916/files/gedupogusasugutubevofemix.pdf
    • https://cdn.shopify.com/s/files/1/0428/2286/0966/files/salesforce_developer_interview_questions.pdf
    • https://cdn.shopify.com/s/files/1/0446/4377/8723/files/arkitektura_e_kompjuterit_agim_cami.pdf
    • https://cdn.shopify.com/s/files/1/0437/2434/1400/files/fepozolabababi.pdf
    • https://cdn.shopify.com/s/files/1/0429/0789/3919/files/kurixajomokidutegamu.pdf
    • https://static.usrfiles.com/ugd/b8c837_963d92698c7844c393e7377a5d1421e7.pdf
    • https://static.usrfiles.com/ugd/b8c837_c207b765a0f34def87e54e84cc07233c.pdf
    • https://static.usrfiles.com/ugd/b8c837_ef2bd8778cf849fd9c7f220d72f0503f.pdf
    • https://static.usrfiles.com/ugd/b8c837_1107cff6c33844f5a82bf5b9e8e08998.pdf
    • https://static.usrfiles.com/ugd/b8c837_81a30c15573c4d93b5b754f527edbcfe.pdf
    • https://cdn.shopify.com/s/files/1/0437/3882/4858/files/how_to_extract_text_from_file.pdf
    • https://cdn.shopify.com/s/files/1/0428/8777/4374/files/rojoze.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_off00006af3.bin
4ab4de4a5da092e304db5c02ef49e5a578d3ee493cc7a277197e235233a6b1a9
pdf-font-stream PDF embedded font (sfnt) at offset 0x6AF3 5448 bytes
font_01_sfnt_off00007d6b.bin
339d688ab1c2e8c64abca03147c5e8ebb8f8ccd0cfbe6112958ecc5d5f3fec72
pdf-font-stream PDF embedded font (sfnt) at offset 0x7D6B 16292 bytes