Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b86d59d6f6e39b4…

MALICIOUS

PDF

50.0 KB Created: 2020-08-30 22:46:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d07cdee21e2b5f1fe00e2d16df360584 SHA-1: 864c4cf5d02098bbec505e582949968ce8ffa4b1 SHA-256: 4b86d59d6f6e39b4e3ea921e2645e395e3f6487c86f7ff555ba148627f0263e0
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link that redirects to a known malicious domain, disguised as an answer key. This is further supported by heuristics indicating a malicious redirector and a PDF link farm. The document body, though heavily obfuscated, contains the malicious URL, confirming its presence within the content.

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=the+muscular+system+chapter+6+answer+key
    • https://static.usrfiles.com/ugd/ac72e0_bf78dc10bced4141a4695f1009dd211f.pdf
    • https://static.usrfiles.com/ugd/f0e51d_f22f693a408240c181f18b49edc9e1e7.pdf
    • https://static.usrfiles.com/ugd/b8c837_486f1f31eea14163a8fc8d6835a42799.pdf
    • https://static.usrfiles.com/ugd/b8c837_44121cb3184d4762b3b64512f465a8bb.pdf
    • https://static.usrfiles.com/ugd/eed56f_db039e85af5643438c6e617aae77cab7.pdf
    • https://static.usrfiles.com/ugd/0aab01_59ddd9398195498a80f5ecf6b3e88324.pdf
    • https://static.usrfiles.com/ugd/b8c837_de39db9160a14e5b852ed7e15ec69196.pdf
    • https://static.usrfiles.com/ugd/b8c837_ed2ec2532ab9414db6307d41b171cbf8.pdf
    • https://cdn.shopify.com/s/files/1/0432/6267/3054/files/kizorovimiroriwupa.pdf
    • https://cdn.shopify.com/s/files/1/0430/1661/8145/files/56079602127.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/lawup.pdf
    • https://static.usrfiles.com/ugd/b8c837_0166657df3834172a13dd5eec9be899b.pdf
    • https://static.usrfiles.com/ugd/5a1791_1e10061df1624074883860a6c2286661.pdf
    • https://static.usrfiles.com/ugd/b98abb_7faa0a642ad7447ab64ff8b9e9e9915e.pdf
    • https://static.usrfiles.com/ugd/b8c837_c63e815e773a4c7ea93a1fa3253f668e.pdf
    • https://static.usrfiles.com/ugd/b0b521_e5d2e812f28d4f6db3be54f75bd48418.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00007615.bin
29018ec96a7e51d48e8d71be5178af76d1f1b009f9866bd23500082bc7175c0b
pdf-font-stream PDF embedded font (sfnt) at offset 0x7615 5256 bytes
font_01_sfnt_off000087e2.bin
dd56fb26fe172b6298ab687faa81c4d0240681a1d28cb97009568e8799293bb2
pdf-font-stream PDF embedded font (sfnt) at offset 0x87E2 10892 bytes
font_02_sfnt_off0000acd3.bin
d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378
pdf-font-stream PDF embedded font (sfnt) at offset 0xACD3 4324 bytes