Malicious PDF — malware analysis report

Static analysis result for SHA-256 526ad1bf231306d7…

MALICIOUS

PDF

68.3 KB Created: 2020-08-15 21:38:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: da9d2c0733b3aa62815d5ff4c3280231 SHA-1: 28673fa45198ce074beef95a12d88729e727a81f SHA-256: 526ad1bf231306d7d38ea911c9529c69ff6b00dfd3920ba64bdefe74b97ec6ac
152 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 obfuscated, includes text related to 'scrambled paragraphs worksheets 8th grade' and the malicious URL, suggesting a lure to educational content. The ML classifier strongly flagged this PDF as malicious, and the presence of a link farm further supports a malicious intent to redirect users to harmful sites.

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/wb?keyword=scrambled%20paragraphs%20worksheets%208th%20grade
    • http://files.launasorensen.com/uploads/1/3/1/1/131163782/moxotikosa.pdf
    • http://files.classoraclemedia.com/uploads/1/3/2/6/132681891/wibujibobutewax.pdf
    • http://bavobunuf.llmea.org/uploads/1/3/0/8/130874254/8175583.pdf
    • http://files.highlandroofingcontractors.co.uk/uploads/1/3/1/3/131398222/7798570.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/kewosa.pdf
    • https://cdn.shopify.com/s/files/1/0428/5857/8086/files/45703568120.pdf
    • https://cdn.shopify.com/s/files/1/0430/6799/8362/files/fuderero.pdf
    • https://cdn.shopify.com/s/files/1/0429/2883/2675/files/36233139802.pdf
    • https://cdn.shopify.com/s/files/1/0438/7612/2779/files/core_workouts.pdf
    • https://cdn.shopify.com/s/files/1/0427/7128/4135/files/fivevisapugelifafizo.pdf
    • https://cdn.shopify.com/s/files/1/0438/9765/1352/files/konubujapozopi.pdf
    • https://cdn.shopify.com/s/files/1/0436/8151/3622/files/38200548585.pdf
    • https://cdn.shopify.com/s/files/1/0429/6084/7004/files/sotukidomekogir.pdf
    • https://cdn.shopify.com/s/files/1/0436/8292/2646/files/vishnu_sahasranamam_lyrics_in_english.pdf
    • https://cdn.shopify.com/s/files/1/0429/3623/8236/files/bixogugaw.pdf
    • https://cdn.shopify.com/s/files/1/0437/0006/0310/files/pokemon_yellow_guide.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_off0000cda3.bin
5f75d60c68ff2cd3b0bb4986bb036f91bde08d1c0ca64a73cb2afba84c8888bd
pdf-font-stream PDF embedded font (sfnt) at offset 0xCDA3 6080 bytes
font_01_sfnt_off0000e230.bin
1288416e834989b63a9a011b6ef2ee72fca9f40cf5d21c095972409089979230
pdf-font-stream PDF embedded font (sfnt) at offset 0xE230 9936 bytes