Malicious PDF — malware analysis report

Static analysis result for SHA-256 0c13c38d0eedd602…

MALICIOUS

PDF

41.0 KB Created: 2020-09-02 00:40:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 25257f24a8aead78cb52790a18c725f4 SHA-1: 145c20f4ece93b64bbc7dd2f1dd168332fb8453d SHA-256: 0c13c38d0eedd602e7a8f392fd0dfeefb38dafdade096110f56ac05b1be39878
162 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains embedded links, one of which points to known malicious redirector infrastructure. The document body text, though partially corrupted, includes language suggesting it is an 'answer key', aligning with the 'SE_INVOICE_LURE' heuristic. The presence of numerous external PDF links, many pointing to benign content, suggests a link farm used to obscure the malicious redirector. No scripts were extracted, but the primary attack vector appears to be social engineering via a malicious link.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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/wix?keyword=ctet.+nic.+in+answer+key+2019
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/cec570_ef215a68b9f74dbdbabf38d204f59454.pdf
    • https://static.usrfiles.com/ugd/ace02d_f19ec547a0514b5ea446893975c3983b.pdf
    • https://static.usrfiles.com/ugd/0d002d_e9fe60d3fdc84fb09759b4fbf36ec7c2.pdf
    • https://static.usrfiles.com/ugd/735189_5546bb42a07c43099ab5cee4cd45e8b8.pdf
    • https://cdn.shopify.com/s/files/1/0463/4414/3005/files/1976_prowler_travel_trailer_owners_manual.pdf
    • https://cdn.shopify.com/s/files/1/0432/6768/6558/files/fosibifisejikinegewevaf.pdf
    • https://cdn.shopify.com/s/files/1/0428/0451/0887/files/17065998732.pdf
    • https://cdn.shopify.com/s/files/1/0437/7644/2519/files/59378556816.pdf
    • https://cdn.shopify.com/s/files/1/0436/7400/9753/files/wildgame_innovations_camera_troubleshooting.pdf
    • https://static.usrfiles.com/ugd/d3758e_05f72654dca74f9a9b5eaac68d3c8f8c.pdf
    • https://static.usrfiles.com/ugd/760101_c991a1c88abe4495a17c132e69f001f5.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_off00006160.bin
1711dfc1bed4249e36b4ca4a9bb5a4b83e48581bb9ee5828d4540e28cd46401e
pdf-font-stream PDF embedded font (sfnt) at offset 0x6160 5436 bytes
font_01_sfnt_off0000740a.bin
d51a6a2a77810f32671d9062db3933a13cca4ec994231abd6bb0b9ff71676dd1
pdf-font-stream PDF embedded font (sfnt) at offset 0x740A 10376 bytes