Malicious PDF — malware analysis report

Static analysis result for SHA-256 665f6c5231212e9f…

MALICIOUS

PDF

35.1 KB Created: 2020-07-08 13:17:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-04
MD5: c4f1a3b58d13694e7f7190b44ad512d3 SHA-1: a9221f965f686eded2ea639958231ebd1c5ed6e9 SHA-256: 665f6c5231212e9f5c09419b708b4a19954ace66cb9e4d5d6408984384cf234a
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links disguised as search results, directing users to potentially malicious websites. The ML classifier strongly indicated maliciousness, and the presence of a redirector link further supports this. The document body text and embedded links suggest a link farm or SEO poisoning tactic to drive traffic to malicious infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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/wb?keyword=introductory%20algebraic%20number%20theory%20pdf In PDF document text
    • http://files.wgchowardcounty.org/uploads/1/3/0/8/130873975/4372205.pdfIn PDF document text
    • http://files.savemetislighthouse.org/uploads/1/3/0/7/130739769/bf9a61739dd.pdfIn PDF document text
    • http://files.hickmanfootball.com/uploads/1/3/0/7/130776788/kamubumul-dobozokowobiz.pdfIn PDF document text
    • http://files.originalsexyslave.com/uploads/1/3/0/9/130969004/ca2abe.pdfIn PDF document text
    • http://files.southlandfamilyclub.com/uploads/1/3/1/3/131379371/e862cb.pdfIn PDF document text
    • http://files.gurdainc.org/uploads/1/3/2/8/132815752/7766636.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://zarupuzagi.files.wordpress.com/2020/06/wajavorabibiwoloribubip.pdfIn PDF document text
    • https://disajunumar650854456.files.wordpress.com/2020/06/21909657829.pdfIn PDF document text
    • https://sibisumimeve.files.wordpress.com/2020/06/10420773665.pdfIn PDF document text
    • https://wakukozid.files.wordpress.com/2020/06/30553946376.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00004f11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x4F11 5452 bytes
SHA-256: 4d7c0dd3bdab6f8c5a72c6c7280818cd9b621f9aa856d47a0c0946d46761a9cd
font_01_sfnt_off00006168.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6168 8940 bytes
SHA-256: 9fed3aa86ad6f39b6527aa806f3a830461631960a7c0109e20984ac2ff8436b7