Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d5a0c3bad3f5f1f…

MALICIOUS

PDF

38.7 KB Created: 2020-10-31 14:17:28 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: a236f0f890c11cd1f6fa1fa1d4a5a3d7 SHA-1: 13f868a84a1a7eadeb5f9cc462267e025dd975e2 SHA-256: 8d5a0c3bad3f5f1f6716d343758fe858ac6493bfc376db3257d65aeecd3f8e20
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded links, with at least one pointing to known malicious redirector infrastructure. The document body, though heavily obfuscated, also contains the URL 'https://ggtraff.ru/aws?keyword=rational+function+worksheet+answers', suggesting a lure to a malicious site. The ML classifier also strongly indicated maliciousness.

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://ggtraff.ru/aws?keyword=rational+function+worksheet+answers
    • https://cdn-cms.f-static.net/uploads/4420020/normal_5f9c545648312.pdf
    • https://dubutabinagi.weebly.com/uploads/1/3/4/4/134441981/zomiwuvax.pdf
    • https://cdn-cms.f-static.net/uploads/4390051/normal_5f92de6785861.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/ea6c9b8b-370d-4aff-a6e1-a94577586cbc/ralph_lauren_return_policy_sale_items.pdf
    • https://uploads.strikinglycdn.com/files/73cebffb-c5c8-4f5d-ba5d-90bb8f16d5da/kumon_answers_level_h_english.pdf
    • https://cdn.shopify.com/s/files/1/0507/1372/3066/files/chinese_jump_rope_hand_patterns.pdf
    • https://s3.amazonaws.com/tesapibebujep/aircraft_autopilot_roll_control_system_project_report.pdf
    • https://s3.amazonaws.com/votubukaxogilix/pdf_to_word_converter_for_macbook_pro.pdf
    • https://s3.amazonaws.com/bevarolimesale/neumonia_tratamiento_antibiotico.pdf
    • https://s3.amazonaws.com/henghuili-files/anatomy_book.pdf
    • https://s3.amazonaws.com/vifusupegiza/kuvenexokigoxigexamurul.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_off00005b74.bin
2ff90ff9d4aabc5e4c441c334d6ac8a6fe65701cc81b48cd84366047db8e9a54
pdf-font-stream PDF embedded font (sfnt) at offset 0x5B74 5132 bytes
font_01_sfnt_off00006cff.bin
fa97e4c178734e002a4167f1702ee8bae00e1f42fece39cd3204e8dcb08818ff
pdf-font-stream PDF embedded font (sfnt) at offset 0x6CFF 9680 bytes