Malicious PDF — malware analysis report

Static analysis result for SHA-256 21dbb796e99f81b2…

MALICIOUS

PDF

42.1 KB Created: 2020-08-08 07:48:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0a0d8711495e9e3184bcd068641ad90e SHA-1: 36aed1d87fe8f2fb335a9fcb81783b259efb6825 SHA-256: 21dbb796e99f81b2d871ae23830fa1f3d492f8a5c01e8443275ef802cae3b24a
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to a link farm hosted on ttraff.ru, a known malicious redirector. The document body itself is heavily obfuscated but contains the malicious URL and numerous links to PDFs hosted on Shopify's CDN. This suggests the primary purpose is to redirect users through malicious infrastructure to potentially malicious content, or to abuse SEO for traffic generation.

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.ru/pify?keyword=radicales+libres+quimica+pdf
    • http://files.prairiewindsorff.com/uploads/1/3/1/4/131453902/e804a76b.pdf
    • http://files.learncprnyc.com/uploads/1/3/1/4/131438759/moxowunoxufogob.pdf
    • http://files.toplinepriority.com/uploads/1/3/1/4/131438888/bemolap.pdf
    • https://cdn.shopify.com/s/files/1/0431/1416/8487/files/guxomerizup.pdf
    • https://cdn.shopify.com/s/files/1/0436/9298/2427/files/50758897955.pdf
    • https://cdn.shopify.com/s/files/1/0434/8903/4402/files/comparing_fractions_with_unlike_denominators.pdf
    • https://cdn.shopify.com/s/files/1/0432/7889/3214/files/software_architecture_design_patterns_in_java_partha_kuchana.pdf
    • https://cdn.shopify.com/s/files/1/0433/8316/0999/files/20429224947.pdf
    • https://cdn.shopify.com/s/files/1/0431/3733/5464/files/arya_samaj_jamnagar.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/9467339244.pdf
    • https://cdn.shopify.com/s/files/1/0430/9817/7693/files/seal_crazy_lyrics.pdf
    • https://cdn.shopify.com/s/files/1/0430/3365/7498/files/68525255727.pdf
    • https://cdn.shopify.com/s/files/1/0430/6331/2533/files/wezebixo.pdf
    • https://cdn.shopify.com/s/files/1/0437/3918/5303/files/60740352999.pdf
    • https://cdn.shopify.com/s/files/1/0431/8072/0294/files/85218585490.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_off00006596.bin
ca53532734d588cddb61702c090305361ff18aa8c29e2a160e716fb30e42e044
pdf-font-stream PDF embedded font (sfnt) at offset 0x6596 5572 bytes
font_01_sfnt_off00007872.bin
7a63c33951aca919afe094ae54b61923677a98b16c95d631a68f421974a78e48
pdf-font-stream PDF embedded font (sfnt) at offset 0x7872 10128 bytes