Malicious PDF — malware analysis report

Static analysis result for SHA-256 a196ff4ab4aab988…

MALICIOUS

PDF

44.1 KB Created: 2020-08-30 22:45:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 258250e6c1fd4fab28498a21c18e4000 SHA-1: ada0e98d07498383f7fb3629fb9a85d94157ae97 SHA-256: a196ff4ab4aab98896158d32fbed52ce498c8f8e421ba1bc75782508500d219d
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, pointing to `https://ttraff.ru/wix?keyword=bank+po+solved+papers+by+kiran+prakashan+pdf`. This URL is likely used to redirect the user to a malicious site. The document body, though heavily obfuscated, also contains this URL and references to PDF papers, reinforcing the lure. Additionally, the PDF exhibits characteristics of a link farm, with numerous embedded links to external PDFs, many hosted on `static.usrfiles.com`.

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=bank+po+solved+papers+by+kiran+prakashan+pdf
    • https://static.usrfiles.com/ugd/b8c837_bf71010f633e4f8f9dcf5413e4d7993d.pdf
    • https://static.usrfiles.com/ugd/95089d_0c43981fed144ddf9b510135b2986766.pdf
    • https://static.usrfiles.com/ugd/e8506d_7193ce96dd124d74b44637228cd267be.pdf
    • https://static.usrfiles.com/ugd/df4650_21d4f788c4a44bd78d12a5ec55dcdefa.pdf
    • https://static.usrfiles.com/ugd/b8c837_aecdab9270964012a74f003896c4ad80.pdf
    • https://static.usrfiles.com/ugd/5ed537_3289937a642044d6a03405ad8523ebdc.pdf
    • https://cdn.shopify.com/s/files/1/0439/1842/6267/files/que_es_una_solucion_hipotonica_isotonica_e_hipertonica.pdf
    • https://cdn.shopify.com/s/files/1/0430/2848/0154/files/dewagipojobido.pdf
    • https://cdn.shopify.com/s/files/1/0437/3633/4501/files/harvard_style_citation_annual_report.pdf
    • https://static.usrfiles.com/ugd/b8c837_8ffb51f4d6df4c81883c0a56039f58f7.pdf
    • https://static.usrfiles.com/ugd/b8c837_a0d5665c94c84289bad72b7396d0bf35.pdf
    • https://static.usrfiles.com/ugd/8b2c09_8b8248b586a64573b67aacadaef55c0a.pdf
    • https://static.usrfiles.com/ugd/45e30f_f1640ed4c3f04edebcda7c7dc2993b31.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_off00005d07.bin
73287d90c451bee104969a3d56bd6312155b678ea192dc0a2471bef08970586d
pdf-font-stream PDF embedded font (sfnt) at offset 0x5D07 5544 bytes
font_01_sfnt_off00006fde.bin
20f4390f7d977c37f9511933a6421c09d43696686994d8c2398d2d1151e1e9d7
pdf-font-stream PDF embedded font (sfnt) at offset 0x6FDE 15920 bytes