Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a4b4b785b01329d…

MALICIOUS

PDF

41.4 KB Created: 2020-08-09 23:27:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0a50ca964fe9c1145af74d441c03380a SHA-1: f8f33ffeaa7b5cafdb3a8d96ac633dfa57477a6a SHA-256: 4a4b4b785b01329d4cd063caa70d23c0fbc813b485f33bfb338d614888c72906
152 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with a critical heuristic firing indicating it links to known malicious redirector infrastructure. The document body text, though partially corrupted, includes a URL that appears to be the primary lure. The ML classifier strongly indicates maliciousness, and the presence of a link farm suggests an attempt to distribute malicious content or engage in SEO abuse.

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.com/pify?keyword=applied+functional+analysis+pdf
    • http://files.stu-acpa.com/uploads/1/3/1/4/131406535/1966712.pdf
    • http://files.ravenclimbing.com/uploads/1/3/1/3/131398197/c4cb545fd2.pdf
    • http://files.norfolkcellolessons.co.uk/uploads/1/3/1/4/131437832/783334.pdf
    • https://cdn.shopify.com/s/files/1/0428/4035/9068/files/batamar.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/89120948070.pdf
    • https://cdn.shopify.com/s/files/1/0437/6949/5710/files/17726605705.pdf
    • https://cdn.shopify.com/s/files/1/0430/4686/2997/files/62866953193.pdf
    • https://cdn.shopify.com/s/files/1/0434/2883/9586/files/digital_marketing_ebooks_free_download.pdf
    • https://cdn.shopify.com/s/files/1/0434/0213/3667/files/linexexunamanuzelenisabev.pdf
    • https://cdn.shopify.com/s/files/1/0429/0550/1852/files/desenesipagagusupater.pdf
    • https://cdn.shopify.com/s/files/1/0437/8342/2109/files/beatles_here_comes_the_sun_piano.pdf
    • https://cdn.shopify.com/s/files/1/0439/5863/2606/files/sokepesowinijajixewizu.pdf
    • https://cdn.shopify.com/s/files/1/0438/6390/0315/files/76100031328.pdf
    • https://cdn.shopify.com/s/files/1/0433/9564/5589/files/devadawujogujofejax.pdf
    • https://cdn.shopify.com/s/files/1/0444/2321/7318/files/pdf_accessibility_checker_software.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/
    • https://cdn.shopify.com/s/files/1/0439/5863/2606/files/sokepesowinijajixewizu.pd

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006421.bin
2d9bf5fb19c19901b0c9266118a9aaa2402b3817331e315b97827b6530973f99
pdf-font-stream PDF embedded font (sfnt) at offset 0x6421 5144 bytes
font_01_sfnt_off000075cb.bin
cae74e76c531ef27206ad16ebbcfa47261bd02f17e3336ea97c7f90f13700c65
pdf-font-stream PDF embedded font (sfnt) at offset 0x75CB 10120 bytes