Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f16b15c301312d4…

MALICIOUS

PDF

36.3 KB Created: 2020-08-30 23:16:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2a2089769200dc6d8287cfa56e57fd31 SHA-1: 7e3f2850e7751a6518bb4a626e1b06e2eba71ab7 SHA-256: 8f16b15c301312d404f7e799ccddb015161c6406cb860bd01306d78238f91104
154 Risk Score

Malware Insights

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

The PDF contains a malicious redirector link disguised as educational content. The ML classifier strongly indicated maliciousness, and the PDF structure includes a link farm pointing to various external PDFs. The primary malicious IOC is the redirector URL, which is likely used to funnel users to 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/wix?keyword=introduction+to+abstract+mathematics
    • https://static.usrfiles.com/ugd/b8c837_e1de1c023a5a4ace8c1d74a72eafdd2f.pdf
    • https://static.usrfiles.com/ugd/6cfc61_6a435638894f4ef58f57c5eacbf0c346.pdf
    • https://static.usrfiles.com/ugd/d55797_ee4e0fe7110c44a991cbf73fa135bbe2.pdf
    • https://static.usrfiles.com/ugd/b8c837_5714bae28ead4cc998467ce501fe75ef.pdf
    • https://static.usrfiles.com/ugd/b8c837_4c41bea29aba489cbd092bdc608078f5.pdf
    • https://cdn.shopify.com/s/files/1/0440/8626/3960/files/pefefe.pdf
    • https://cdn.shopify.com/s/files/1/0430/7773/0464/files/48093555819.pdf
    • https://cdn.shopify.com/s/files/1/0435/1547/8176/files/rajef.pdf
    • https://cdn.shopify.com/s/files/1/0440/7758/0453/files/29060373362.pdf
    • https://cdn.shopify.com/s/files/1/0436/1525/6738/files/jack_lalanne.pdf
    • https://cdn.shopify.com/s/files/1/0431/7013/6230/files/starry_starry_night_chords.pdf
    • https://cdn.shopify.com/s/files/1/0437/2037/6474/files/nilugoriku.pdf
    • https://cdn.shopify.com/s/files/1/0429/8155/6375/files/jisejuz.pdf
    • https://cdn.shopify.com/s/files/1/0427/5906/1670/files/rijevopovijoriwamipowuke.pdf
    • https://cdn.shopify.com/s/files/1/0429/5314/6517/files/vukirejipopu.pdf
    • https://cdn.shopify.com/s/files/1/0437/3122/2689/files/57003456960.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_off00005134.bin
63ca8f1c901d1908cdf5715d2bf2503cd40559831661247263ff429b93dee9c1
pdf-font-stream PDF embedded font (sfnt) at offset 0x5134 5224 bytes
font_01_sfnt_off000062be.bin
0aeafb1430df2f5ac58cd0b562983607052423dcee14d402d9bb80caee945a0e
pdf-font-stream PDF embedded font (sfnt) at offset 0x62BE 9832 bytes