Malicious PDF — malware analysis report

Static analysis result for SHA-256 55dffa706b76b2dd…

MALICIOUS

PDF

40.3 KB Created: 2020-08-10 10:11:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 232aaf50a6c23e6eff5298408981c19b SHA-1: 253a5694ee5d2ca0f14a5a48a67e15cfde09c466 SHA-256: 55dffa706b76b2dd388fd1498e25a89ce92e0639be3ef78fb1fdf3f286193c88
154 Risk Score

Malware Insights

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

The PDF contains a malicious redirector link disguised as information about school holidays. The PDF_MALICIOUS_REDIRECTOR_LINK heuristic firing confirms the link leads to known malicious infrastructure. The ML_NYX_PDF_MALICIOUS score indicates a high probability of malicious intent. The document body, though heavily obfuscated, contains the URL that is likely intended to lure the user to a malicious site.

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.com/pify?keyword=aberdeenshire+council+school+holidays+pdf
    • http://sulisidov.abby-humphreys.com/uploads/1/3/1/3/131380600/8644505.pdf
    • http://files.asechrestspencer.com/uploads/1/3/1/4/131452887/549bb8.pdf
    • http://files.secondhomeba.com/uploads/1/3/0/7/130740112/jozixusivizeladuxixi.pdf
    • http://files.skywartooth.com/uploads/1/3/1/8/131872087/kakilumo.pdf
    • http://tozirut.outonalimbdance.com/uploads/1/3/1/6/131636725/2645019.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/92702877098.pdf
    • https://cdn.shopify.com/s/files/1/0439/5817/3854/files/dolakopukirujejelabu.pdf
    • https://cdn.shopify.com/s/files/1/0432/8462/7624/files/zatixibutasebuboteno.pdf
    • https://cdn.shopify.com/s/files/1/0435/0243/6512/files/18638862782.pdf
    • https://cdn.shopify.com/s/files/1/0430/1455/3763/files/56532367834.pdf
    • https://cdn.shopify.com/s/files/1/0431/3602/4742/files/63396149954.pdf
    • https://cdn.shopify.com/s/files/1/0438/8916/4440/files/71516551979.pdf
    • https://cdn.shopify.com/s/files/1/0434/8382/4294/files/bekorutolifipup.pdf
    • https://cdn.shopify.com/s/files/1/0437/6123/8168/files/nagajuk.pdf
    • https://cdn.shopify.com/s/files/1/0430/8946/1410/files/wuvidomesilagajojuwi.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/41557636134.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_off00005f79.bin
7cb382dd5f7cb20b1e99e236e865407f8e661d902e9b7193ec8126d72e2eebaf
pdf-font-stream PDF embedded font (sfnt) at offset 0x5F79 5472 bytes
font_01_sfnt_off00007218.bin
9fd001b4f27e59fb5f4a164cf77a4d26efaf51f33140a3446dbc39d167d99289
pdf-font-stream PDF embedded font (sfnt) at offset 0x7218 9836 bytes