Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3a6edca72413f1c…

MALICIOUS

PDF

43.2 KB Created: 2020-08-10 02:42:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: dc7f5416769ec169e596ac6753d57c63 SHA-1: 4f28edff4d5f53ad3a6f8d104385d44ad50af578 SHA-256: a3a6edca72413f1c8b76beeb0f6b7d81ad3d9d4df4c52dbd1ca2f9e6f16aa827
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to external resources. One critical heuristic firing indicates that the PDF links to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains a URL that appears to be the primary lure. The ML classifier strongly supports the malicious nature of this PDF.

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.ru/pify?keyword=nikola+tesla+books+pdf
    • http://files.cohinteriors.com/uploads/1/3/0/8/130814907/9053380.pdf
    • http://files.positiveculture.org/uploads/1/3/2/3/132302894/6944347.pdf
    • http://files.obriendevelopments.org/uploads/1/3/1/3/131397987/adbd9b1bb63.pdf
    • https://cdn.shopify.com/s/files/1/0435/5004/8420/files/bengali_english_calendar_2020.pdf
    • https://cdn.shopify.com/s/files/1/0437/8555/2034/files/belimbing_wuluh_untuk_hipertensi.pdf
    • https://cdn.shopify.com/s/files/1/0435/6728/4387/files/big_ideas_simply_explained_politics.pdf
    • https://cdn.shopify.com/s/files/1/0437/6385/9605/files/samsung_mtp_driver.pdf
    • https://cdn.shopify.com/s/files/1/0428/0988/4838/files/expand_all_columns_excel.pdf
    • https://cdn.shopify.com/s/files/1/0430/7124/2389/files/zenanigilabofonoliwetu.pdf
    • https://cdn.shopify.com/s/files/1/0433/6628/5464/files/58430359383.pdf
    • https://cdn.shopify.com/s/files/1/0429/6278/0311/files/vexiwezususuba.pdf
    • https://cdn.shopify.com/s/files/1/0435/3651/5224/files/19068989107.pdf
    • https://cdn.shopify.com/s/files/1/0428/3459/1907/files/96543468482.pdf
    • https://cdn.shopify.com/s/files/1/0429/5802/8959/files/51727889676.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_off0000694b.bin
8442198728880bcdd0de3a0d16493578a7eecfc840629b29b39036adac74a73d
pdf-font-stream PDF embedded font (sfnt) at offset 0x694B 5112 bytes
font_01_sfnt_off00007ac6.bin
0a2769d0b632af3e9f3b32053227e9283e8b35cbe59fc8c1259c3937603aa5a2
pdf-font-stream PDF embedded font (sfnt) at offset 0x7AC6 11048 bytes