Malicious PDF — malware analysis report

Static analysis result for SHA-256 31a5f002d803da7b…

MALICIOUS

PDF

43.8 KB Created: 2020-08-12 07:06:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0ef616bfcabbb7f570826dbbba3ec404 SHA-1: 04c6c7607b1729109496c531f986c720b60562ce SHA-256: 31a5f002d803da7b46cde3ce0413acbb7fe5b5d3cfb14e3b47100a10b774e399
152 Risk Score

Malware Insights

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

The PDF contains a prominent link disguised as a Dell Vostro 3400 user manual, directing users to a malicious redirector. The heuristic PDF_MALICIOUS_REDIRECTOR_LINK confirms this, and the ML classifier strongly indicates malicious intent. The document appears to be part of a link farm designed for SEO poisoning to attract unsuspecting users.

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/wb?keyword=dell%20vostro%203400%20user%20manual%20pdf
    • http://files.newlifeduarte.org/uploads/1/3/1/4/131407849/2121610.pdf
    • http://files.slusarenko.ca/uploads/1/3/1/6/131607440/37a964c7a.pdf
    • http://files.stjohnsdunellen.org/uploads/1/3/1/6/131606046/ee04d81830cd9a.pdf
    • https://cdn.shopify.com/s/files/1/0428/2961/1171/files/93180836425.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/gowavofopinesifaremoka.pdf
    • https://cdn.shopify.com/s/files/1/0434/1393/0142/files/gokovifisavelotumaselazeb.pdf
    • https://cdn.shopify.com/s/files/1/0430/7540/3936/files/gefadogotiwa.pdf
    • https://cdn.shopify.com/s/files/1/0445/6228/4703/files/the_admirable_crichton_summary.pdf
    • https://cdn.shopify.com/s/files/1/0437/1097/2053/files/zunavuzokonikobux.pdf
    • https://cdn.shopify.com/s/files/1/0429/9145/2313/files/giluredufepa.pdf
    • https://cdn.shopify.com/s/files/1/0436/2846/2233/files/zip_code_us.pdf
    • https://cdn.shopify.com/s/files/1/0433/1290/6405/files/98046785241.pdf
    • https://cdn.shopify.com/s/files/1/0432/1955/0370/files/93486858587.pdf
    • https://cdn.shopify.com/s/files/1/0434/8031/8118/files/calendario_escolar_cantabria_2020_20.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_off00006aef.bin
2004843f2b34a46217626cc152196f1d040cbfc8a4db00071020b538c69e5dca
pdf-font-stream PDF embedded font (sfnt) at offset 0x6AEF 5640 bytes
font_01_sfnt_off00007e17.bin
ee85d7b5e6f9de565fce02ddb87dde042572c1e4d2f5b5175bbdfddf5d663c45
pdf-font-stream PDF embedded font (sfnt) at offset 0x7E17 10772 bytes