Malicious PDF — malware analysis report

Static analysis result for SHA-256 1236b4da7fbe4505…

MALICIOUS

PDF

47.3 KB Created: 2020-09-04 00:07:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 546d0ea01127e0e7353363cfda79e5b2 SHA-1: 48960511f4913df7ffbf04b123097733e9f70e7e SHA-256: 1236b4da7fbe45054224e1300daabea2e99677c7fa39e4e6d9eec0034109973d
154 Risk Score

Malware Insights

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

The PDF contains numerous links, including one to a known malicious redirector, disguised as interview questions. The ML classifier strongly indicates maliciousness. The embedded URLs suggest a link farm or SEO poisoning tactic to drive traffic to malicious sites.

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=basic+computer+science+interview+questions+and+answers
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/6908d7_d76fd6af31fa408ca26bf5b5491c39c8.pdf
    • https://static.usrfiles.com/ugd/e3834b_bad9e4c76b15438eb23f539cd1b7c8ca.pdf
    • https://static.usrfiles.com/ugd/0c41e7_06dbfe6cd20041a1abb1750dfc8a0687.pdf
    • https://cdn.shopify.com/s/files/1/0431/1672/4386/files/le_conformisme_citation.pdf
    • https://cdn.shopify.com/s/files/1/0437/7693/4042/files/33188472493.pdf
    • https://cdn.shopify.com/s/files/1/0454/9489/4744/files/bagasobe.pdf
    • https://cdn.shopify.com/s/files/1/0433/5848/6678/files/pataloburagira.pdf
    • https://cdn.shopify.com/s/files/1/0432/7853/2758/files/treatment_of_amoebic_liver_abscess.pdf
    • https://cdn.shopify.com/s/files/1/0462/5891/3431/files/xodovovurisegaruli.pdf
    • https://cdn.shopify.com/s/files/1/0428/1214/5823/files/97423220810.pdf
    • https://cdn.shopify.com/s/files/1/0434/7396/1110/files/38937343281.pdf
    • https://cdn.shopify.com/s/files/1/0462/9174/6977/files/graphics_card_games_for_pc_free.pdf
    • https://cdn.shopify.com/s/files/1/0430/6924/3553/files/between_the_sheets_meaning_in_tamil.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/febipak.pdf
    • https://cdn.shopify.com/s/files/1/0431/0967/9265/files/diremobepokideviwodikibib.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_off00007a80.bin
170272599df190a5b44a73b61488b4ccf54c44fa86813205458144b2f2596cd4
pdf-font-stream PDF embedded font (sfnt) at offset 0x7A80 5516 bytes
font_01_sfnt_off00008d36.bin
c72d2df0ab6d965b30e0e1eedb42c849538f72896185a93f58d361c79bd17644
pdf-font-stream PDF embedded font (sfnt) at offset 0x8D36 10120 bytes