Malicious PDF — malware analysis report

Static analysis result for SHA-256 38f16b4a2580c034…

MALICIOUS

PDF

42.0 KB Created: 2020-08-17 15:59:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: fc351f40381565e193a62ac8c6199a76 SHA-1: 6dcf34840b369331482f48b0958530619e8bc8d8 SHA-256: 38f16b4a2580c034fc3f6a4004c4fb80b99f549bd5bef9c5667bf2bca4141fbd
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains a link to a known malicious redirector, ttraff.ru, disguised as a search result for 'cognitive behavioral family therapy pdf'. The ML classifier strongly indicates maliciousness. The document body, though heavily obfuscated, contains the same malicious URL and numerous other URLs pointing to Shopify-hosted PDFs, suggesting a link farm or SEO poisoning tactic to distribute malicious content. The primary attack vector appears to be social engineering via a deceptive document title and embedded links.

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/pify?keyword=cognitive+behavioral+family+therapy+pdf
    • http://files.podlashuc.com/uploads/1/3/0/7/130739747/bijaru-nedopuleloke-gutowatokududux.pdf
    • https://cdn.shopify.com/s/files/1/0431/0394/4858/files/pukujo.pdf
    • https://cdn.shopify.com/s/files/1/0434/3755/5864/files/71105621280.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/75904593322.pdf
    • https://cdn.shopify.com/s/files/1/0432/8646/2620/files/citation_circle_xkcd.pdf
    • https://cdn.shopify.com/s/files/1/0430/6819/4978/files/33168044508.pdf
    • https://cdn.shopify.com/s/files/1/0432/6624/4766/files/2631245100.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/fulefevizurosojasi.pdf
    • https://cdn.shopify.com/s/files/1/0433/8873/1546/files/jolelekoruvutevuzokosi.pdf
    • https://cdn.shopify.com/s/files/1/0435/4323/2661/files/gadutesokisurego.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/borutazaweluv.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/riwemabosemuridaredexe.pdf
    • https://cdn.shopify.com/s/files/1/0438/6829/1232/files/wizazitolevegoro.pdf
    • https://cdn.shopify.com/s/files/1/0435/1708/3803/files/tigativa.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_off0000652e.bin
031dec6757da8ccc5a0c27e9b6b78d02121f7c824bcfe220053184db949147b1
pdf-font-stream PDF embedded font (sfnt) at offset 0x652E 5484 bytes
font_01_sfnt_off000077b0.bin
9f89e5bdd2f43b6c8d7e5e50cd330ce927934bdfccbebe3876edf88f633be4fa
pdf-font-stream PDF embedded font (sfnt) at offset 0x77B0 10504 bytes