Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b5ed801b767969d…

MALICIOUS

PDF

45.1 KB Created: 2020-03-30 04:00:43 +03:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6)
MD5: cd97d2dea7adb8875b9051d079ad3d84 SHA-1: 9e3088d838fb3bf46240878c5873150a816e22f3 SHA-256: 4b5ed801b767969d4e2d1dc7dbca18dac0f433768f15a8f296d5868161fd8182
94 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a large number of external links, many of which point to similarly structured URLs on different domains. This pattern is indicative of a link farm or SEO spam campaign. The document body, though partially corrupted, contains the title 'Ejercicios de las propiedades de la multiplicacion para primaria', suggesting a lure for educational content. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious link distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • 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.
  • External URI info PDF_URI
    PDF contains an external URL action
  • 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 http://aldensuites.devsite-1.com/uploads/1/3/1/4/131455663/131455663.html#ejercicios+de+las+propiedades+de+la+multiplicacion+para+primaria
    • http://murrayparkcondos.com/uploads/1/3/0/2/130287882/785c37f5b66ba09.pdf
    • http://evylareau.com/uploads/1/3/0/6/130621412/4595870.pdf
    • http://oregonabslearningstandards.org/uploads/1/3/0/2/130271103/d1d85e21e.pdf
    • http://carolinadance.net/uploads/1/3/0/6/130604549/gelugozodo_wevaximoxiwir_gibipazesi.pdf
    • http://latticeworkinvestments.com/uploads/1/3/0/4/130490444/6b2584a.pdf
    • http://www.applesandbooks.com/uploads/1/3/0/6/130621130/16e7f6999ef39e.pdf
    • http://artisticoctopus.com/uploads/1/3/0/7/130739387/fulej.pdf
    • http://footballidcamps.net/uploads/1/3/1/1/131163620/witetijugasun_padolatil.pdf
    • http://republicanswithballs.com/uploads/1/3/0/7/130738503/gesibisuvujibar_jekevil_kezesura_bogasumerone.pdf
    • http://cquartspaceweeblyonline.com/uploads/1/3/1/0/131070560/samenebasaji_soxozadugoko.pdf
    • http://shibaboss.com/uploads/1/3/0/5/130550880/dunav.pdf
    • http://jwashenik.com/uploads/1/3/0/8/130874304/664ccf6b7.pdf
    • http://draecreations.com/uploads/1/3/0/5/130543870/005f5242.pdf
    • http://radtacular.net/uploads/1/3/0/7/130740551/3cef4ac.pdf
    • http://thehairgrowthinsitute.com/uploads/1/3/0/3/130313403/vuxumumoluziso.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_off00006d8d.bin
4aaa784ea0254fc1c6f318a4e69ed5cda35d8f4a03b7c07fff7b13dc6adeb1b9
pdf-font-stream PDF embedded font (sfnt) at offset 0x6D8D 9232 bytes
font_01_sfnt_off00008ed9.bin
c715d70b655cc84612960fb88a4e12085ad92abfa9c7e55edaa865827c7872ae
pdf-font-stream PDF embedded font (sfnt) at offset 0x8ED9 16148 bytes