Malicious PDF — malware analysis report

Static analysis result for SHA-256 81cbd8de2475511c…

MALICIOUS

PDF

39.7 KB Created: 2020-08-30 18:53:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c9498316e8baf14c1d437c91dcee587a SHA-1: 637a0d268fdf62170898c8c19d4302e12021e0a9 SHA-256: 81cbd8de2475511c7971fe052cd81787a46918bdf7b6545a76ddbbc9ba9afc40
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged as malicious due to a high number of embedded external links, with one specifically pointing to known malicious redirector infrastructure. The ML classifier also strongly indicated maliciousness. The document body, though heavily obfuscated, contains the URL https://ttraff.ru/wix?keyword=perfect+snake+skin+rdr2, which is likely the primary malicious destination.

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/wix?keyword=perfect+snake+skin+rdr2
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/ae059d_0bde720c112e4cf1b3993cd2bd089cc9.pdf
    • https://static.usrfiles.com/ugd/0779a3_75d7755124c34c2fa0930768fa471d19.pdf
    • https://static.usrfiles.com/ugd/b8c837_dd8067f5b2084320aa965e22ea9ccd1f.pdf
    • https://cdn.shopify.com/s/files/1/0437/1097/2053/files/41708013394.pdf
    • https://cdn.shopify.com/s/files/1/0433/2371/9845/files/64707106418.pdf
    • https://cdn.shopify.com/s/files/1/0427/8150/7740/files/magical_jelly_bean_keyfinder.pdf
    • https://cdn.shopify.com/s/files/1/0433/8050/6773/files/77349767476.pdf
    • https://cdn.shopify.com/s/files/1/0433/4387/2150/files/rulebusotulu.pdf
    • https://cdn.shopify.com/s/files/1/0437/3191/0821/files/haryana_bjp_candidate_list.pdf
    • https://cdn.shopify.com/s/files/1/0434/8539/7152/files/informacion_sobre_el_camino_de_santiago_wikipedia.pdf
    • https://cdn.shopify.com/s/files/1/0432/3350/9534/files/saxezadasusogavatedo.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005f31.bin
2742136695c4a3899b2a3f2a96c3a3ee752f6ef2656815a0863e0f5a98cd4d4b
pdf-font-stream PDF embedded font (sfnt) at offset 0x5F31 5180 bytes
font_01_sfnt_off000070d9.bin
a1571fcc3bd5d1b9e4010660544087553546c84454622881b150781da5127131
pdf-font-stream PDF embedded font (sfnt) at offset 0x70D9 9824 bytes