Malicious PDF — malware analysis report

Static analysis result for SHA-256 78aa1949defe1acb…

MALICIOUS

PDF

50.1 KB Created: 2020-08-31 13:46:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 60537f3334e8acb4fae22d5fe6d5e829 SHA-1: b209736d53a00c4a36790bb76c6e683cea1c6290 SHA-256: 78aa1949defe1acbfd8da13d95950ac28a6d360e7c8985b64b24d02e5e64f439
154 Risk Score

Malware Insights

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

The PDF contains embedded links that redirect to a known malicious infrastructure, specifically a URL designed to look like comments on a school report card. The heuristic PDF_MALICIOUS_REDIRECTOR_LINK and the ML classifier strongly indicate malicious intent. The presence of numerous external PDF links also suggests a link farm, potentially for SEO manipulation or distributing further malicious 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.cc/pify?keyword=comments+on+primary+school+report+card
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/4b874d_a19ae136d6004b6ea73a07d1615a3f94.pdf
    • https://static.usrfiles.com/ugd/36f25b_4e889c7aaf424c179454a68183cff0f1.pdf
    • https://static.usrfiles.com/ugd/a1fb72_7798455ceeff4c09a7841ae4842d307a.pdf
    • https://static.usrfiles.com/ugd/d5415a_31b5f907724f4164b8c1d36b50040592.pdf
    • https://static.usrfiles.com/ugd/429b25_e9c29c02bd9d4d0eb8037fcb75293632.pdf
    • https://static.usrfiles.com/ugd/b85eb0_110d0edf10064e408479821c5ec44119.pdf
    • https://static.usrfiles.com/ugd/b8c837_48d56d99f5db44099dd19650b14b9f03.pdf
    • https://static.usrfiles.com/ugd/b8c837_88ca40505ca84e849957cd6520c240bc.pdf
    • https://static.usrfiles.com/ugd/b8c837_ada084d37453491c81c6fd609163feab.pdf
    • https://cdn.shopify.com/s/files/1/0429/2457/2835/files/bebras_challenge_2020.pdf
    • https://cdn.shopify.com/s/files/1/0433/5258/8437/files/doberefopaxa.pdf
    • https://cdn.shopify.com/s/files/1/0432/2400/6820/files/ashby_jones_engineering_materials.pdf
    • https://static.usrfiles.com/ugd/e4a001_f4d2d078b4c04e8eaaf830aab9545242.pdf
    • https://static.usrfiles.com/ugd/432b07_4574682ae3eb493b9421938525b847f2.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_off00008685.bin
e0280c5c10fb94e59e1e51a97dcf2ae0f783976e9aab28581f7d2607f4545597
pdf-font-stream PDF embedded font (sfnt) at offset 0x8685 5320 bytes
font_01_sfnt_off0000986f.bin
d505602f244c2a50870875e8c9b2e536948b8aa06d24e342ff36f76cf0734120
pdf-font-stream PDF embedded font (sfnt) at offset 0x986F 10088 bytes