Malicious PDF — malware analysis report

Static analysis result for SHA-256 55c2e2b617e8ec32…

MALICIOUS

PDF

61.7 KB Created: 2020-08-11 01:01:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: dec7ff91f32bc05405b6ad8bde7b15d5 SHA-1: 840e102821e8344f592dbcddc122c44f8b26e827 SHA-256: 55c2e2b617e8ec32a3cdbaaed9f56d530bded4c2eb84fc14d4d797d554d15c80
152 Risk Score

Malware Insights

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

The PDF document was flagged as malicious by an ML classifier and contains a critical heuristic indicating it links to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains a URL that appears to be a lure for 'protein synthesis steps pdf'. The PDF also contains a mass of external links, many hosted on Shopify, suggesting a link farm or SEO poisoning tactic to distribute malicious content. The primary malicious IOC is the redirector URL.

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=protein+synthesis+steps+pdf
    • http://files.jacksonandthepoolsharks.com/uploads/1/3/1/3/131398221/wesixukin.pdf
    • http://files.centralbusinessdistrict.com/uploads/1/3/2/8/132814989/13cd3627f8.pdf
    • http://vinade.moniestorm.com/uploads/1/3/1/3/131380213/parakirusu.pdf
    • https://cdn.shopify.com/s/files/1/0437/1516/6357/files/10213151753.pdf
    • https://cdn.shopify.com/s/files/1/0435/5008/1183/files/hard_reset_ipod.pdf
    • https://cdn.shopify.com/s/files/1/0428/1021/2518/files/71565604917.pdf
    • https://cdn.shopify.com/s/files/1/0439/3956/1630/files/quimica_inorganica_catherine_housecroft.pdf
    • https://cdn.shopify.com/s/files/1/0432/5844/5979/files/xowuzo.pdf
    • https://cdn.shopify.com/s/files/1/0434/3968/5799/files/suzakomipofuvib.pdf
    • https://cdn.shopify.com/s/files/1/0433/8617/5651/files/kuximufuwur.pdf
    • https://cdn.shopify.com/s/files/1/0431/3179/7668/files/pasenuxavatovekewuvizi.pdf
    • https://cdn.shopify.com/s/files/1/0432/6028/0982/files/all_constitutional_amendments.pdf
    • https://cdn.shopify.com/s/files/1/0428/1679/8883/files/28841058571.pdf
    • https://cdn.shopify.com/s/files/1/0431/0958/0961/files/properties_of_bearing_materials.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_off0000b55b.bin
91a1c65ebf379c41b61e910f734f0d57e6b5a2ff4cf18b59ceb910c0845ce24c
pdf-font-stream PDF embedded font (sfnt) at offset 0xB55B 4988 bytes
font_01_sfnt_off0000c652.bin
13d34848518564dc2f2cae7db1d2cf2425377bcdfcc45f57d888a94a2ab37866
pdf-font-stream PDF embedded font (sfnt) at offset 0xC652 10452 bytes