Malicious PDF — malware analysis report

Static analysis result for SHA-256 b917a3ebb9737cb8…

MALICIOUS

PDF

42.2 KB Created: 2020-08-31 18:07:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1c7dd39c5e359e1202fb5626a6724a4e SHA-1: 7f04664ac6e8b5a16a84aefc7d5a63b568fd50ea SHA-256: b917a3ebb9737cb8851fcdb7617f4c25977029d6207cda09ef251b4337b28fb8
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 infrastructure, specifically `https://ttraff.club/wix?keyword=android+wear+os+emulator`. This indicates a phishing or social engineering attempt to lure users to a malicious site. The presence of a large number of external PDF links, many pointing to `static.usrfiles.com`, suggests a link farm or SEO poisoning technique to improve search engine ranking for malicious content. The ML classifier also strongly flagged this PDF as malicious.

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.club/wix?keyword=android+wear+os+emulator
    • https://static.usrfiles.com/ugd/87a178_bb9ca08811eb4c5e99d6778724d50667.pdf
    • https://static.usrfiles.com/ugd/7f16bd_e9e44a44f50240afaf9d7c4379b86d38.pdf
    • https://static.usrfiles.com/ugd/764aaa_baa992162ccd4f2096c7c0bb307205e7.pdf
    • https://static.usrfiles.com/ugd/c3548c_4d5d7c4bbb7448c48319da1e6fad949c.pdf
    • https://static.usrfiles.com/ugd/2b3f46_b599b3d2899443afa4b8c3bf05bbc905.pdf
    • https://cdn.shopify.com/s/files/1/0440/2659/3445/files/hp_patwari_question_paper_with_answer.pdf
    • https://cdn.shopify.com/s/files/1/0434/0393/5911/files/rixexaraxemonemexix.pdf
    • https://cdn.shopify.com/s/files/1/0431/2432/6564/files/how_to_pair_corsair_void_pro_wireless.pdf
    • https://static.usrfiles.com/ugd/b8c837_a8de0b5250514b5fb7de2c281ec5ba82.pdf
    • https://static.usrfiles.com/ugd/b8c837_9b7fd98a56984821900bff5466b75b4a.pdf
    • https://static.usrfiles.com/ugd/34e21e_a573931821dd4c98a751f77d5967b362.pdf
    • https://static.usrfiles.com/ugd/7f46b5_dce440f548444496bbc77f0957804c6b.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_off000062c7.bin
f86de1b2b9943c9c2604edea5b47701d064efa0a9bed355875409a38c6268edf
pdf-font-stream PDF embedded font (sfnt) at offset 0x62C7 5052 bytes
font_01_sfnt_off000073ea.bin
737772e064bf992c197795821c522b12cf6840cd302557630646713a0845c212
pdf-font-stream PDF embedded font (sfnt) at offset 0x73EA 12768 bytes