Malicious PDF — malware analysis report

Static analysis result for SHA-256 5486b8930fdbf3c1…

MALICIOUS

PDF

43.5 KB Created: 2020-08-17 07:56:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2caa0e978b22caa6dc41fecfab2b43b9 SHA-1: 16ccb4ba362266401fa3ad3889d6c240513467fa SHA-256: 5486b8930fdbf3c10e51f67453ff3c119c35a1e987efcb72775f765f3c8e62fd
154 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with one specifically pointing to a known malicious redirector. The document body, though partially corrupted, suggests an attempt to disguise itself as an educational worksheet to entice users to click on these links. The ML classifier strongly flagged this PDF as malicious, supporting the conclusion that it is designed for malicious redirection.

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=algebra+1+solving+linear+equations+worksheet
    • http://rojuve.usgrandmasters.com/uploads/1/3/1/4/131408899/texomudoza-fugemiwo-zivojasuzukot.pdf
    • http://files.ustars.org/uploads/1/3/2/8/132814196/fibal.pdf
    • http://files.allnationscoast.net/uploads/1/3/1/8/131857419/vuwewo.pdf
    • http://files.heartofillinoisorff.org/uploads/1/3/1/0/131070982/7a536d.pdf
    • https://cdn.shopify.com/s/files/1/0429/6825/2565/files/lexedajunuwapafukumobugan.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/7614883084.pdf
    • https://cdn.shopify.com/s/files/1/0446/7684/1635/files/face_slap_sound_effect_free.pdf
    • https://cdn.shopify.com/s/files/1/0428/8443/2031/files/84793774584.pdf
    • https://cdn.shopify.com/s/files/1/0438/2906/7933/files/capacitacion_aprendizajes_clave_preescolar.pdf
    • https://cdn.shopify.com/s/files/1/0428/9468/8412/files/nimulizewage.pdf
    • https://cdn.shopify.com/s/files/1/0431/4864/0418/files/99149099246.pdf
    • https://cdn.shopify.com/s/files/1/0433/3184/6296/files/1275695613.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_off00006b51.bin
f12960a3d94cefd9c184a193db85cde401bab0ee722e6130ede2c5c990a3c46c
pdf-font-stream PDF embedded font (sfnt) at offset 0x6B51 5472 bytes
font_01_sfnt_off00007e04.bin
557535776c611cf7b5c3b1f51f2843177f92d3e67ed94bf36400fa781b468929
pdf-font-stream PDF embedded font (sfnt) at offset 0x7E04 10340 bytes