Malicious PDF — malware analysis report

Static analysis result for SHA-256 f50258ca5bc85944…

MALICIOUS

PDF

42.6 KB Created: 2020-08-08 06:12:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e8724a5a2257180971b3741f58d4e730 SHA-1: 6f95fceb70fb2fe03561777e7916bde902641e19 SHA-256: f50258ca5bc85944dffed591d4aabec2a6d7dc15507355b4e5d4b083b056570a
154 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for a malicious redirector link, specifically pointing to 'https://ttraff.cc/pify?keyword=ansys+acoustics+pdf'. This indicates the document's primary purpose is to redirect the user to malicious infrastructure. The presence of a large number of external PDF links, many hosted on cdn.shopify.com, suggests a link farm SEO tactic to improve search engine ranking and visibility for the malicious redirector. The ML classifier also strongly flagged this PDF as malicious.

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/pify?keyword=ansys+acoustics+pdf
    • http://files.volunteerteachkenya.net/uploads/1/3/1/4/131452953/7f4c093b5b5acf.pdf
    • http://files.bentnotbrokenscoliosis.com/uploads/1/3/2/6/132681885/2425351.pdf
    • http://files.stgabrielpgh.org/uploads/1/3/1/6/131607321/nunov.pdf
    • https://cdn.shopify.com/s/files/1/0435/8553/6161/files/boise_idaho_tv_listings.pdf
    • https://cdn.shopify.com/s/files/1/0431/8576/6561/files/71945867116.pdf
    • https://cdn.shopify.com/s/files/1/0431/2242/6013/files/19229111426.pdf
    • https://cdn.shopify.com/s/files/1/0428/5536/6822/files/performance_appraisal_format.pdf
    • https://cdn.shopify.com/s/files/1/0433/4406/8773/files/nature_and_scope_of_business_plan.pdf
    • https://cdn.shopify.com/s/files/1/0434/0537/7701/files/71250420974.pdf
    • https://cdn.shopify.com/s/files/1/0430/8297/3346/files/24622392042.pdf
    • https://cdn.shopify.com/s/files/1/0428/8312/1319/files/22278284379.pdf
    • https://cdn.shopify.com/s/files/1/0435/4693/5451/files/ielts_journal_writing_task_1_general.pdf
    • https://cdn.shopify.com/s/files/1/0437/4790/1592/files/43430254731.pdf
    • https://cdn.shopify.com/s/files/1/0431/8055/6452/files/77716161908.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_off00006981.bin
843cba716fa640a8d91bc62c737ee4d94332545a4e272c17437c8491901e1840
pdf-font-stream PDF embedded font (sfnt) at offset 0x6981 5112 bytes
font_01_sfnt_off00007b0d.bin
3f7377380ccf08a9d9db97ca4b6431d8ba22d2f6be04c6ece527faf6a37f589a
pdf-font-stream PDF embedded font (sfnt) at offset 0x7B0D 10244 bytes