Malicious PDF — malware analysis report

Static analysis result for SHA-256 b904c1647e1fbffd…

MALICIOUS

PDF

46.6 KB Created: 2020-08-10 13:19:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2c6fe23f1d8a5834e86356e1c4e7041c SHA-1: 26b94c0bfa3cdde193f4c3fdd12cd390d31a2257 SHA-256: b904c1647e1fbffd7e02c4f2426e22d7a90b6e1f7d14e9244cb2944811ac6664
154 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded links, many of which point to external PDF files hosted on various domains. One critical heuristic firing indicates that a link within the document redirects to known malicious infrastructure. The ML classifier also flagged this PDF as malicious with high confidence. The document body, though heavily obfuscated, contains the URL that is also flagged as malicious.

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=array+in+php+tutorial+pdf
    • http://files.littlehandshomedaycare.net/uploads/1/3/1/3/131383478/2121861.pdf
    • http://files.matthewwolosz.com/uploads/1/3/0/7/130739387/sijav.pdf
    • http://files.worldiqchallenge.com/uploads/1/3/1/3/131382092/telibunepabo-nizotimepe-kivinuse.pdf
    • https://cdn.shopify.com/s/files/1/0432/6991/4782/files/42963507355.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/30617095305.pdf
    • https://cdn.shopify.com/s/files/1/0433/0641/8331/files/inject_malicious_code_in.pdf
    • https://cdn.shopify.com/s/files/1/0429/4197/2636/files/gafakakerel.pdf
    • https://cdn.shopify.com/s/files/1/0430/1769/9477/files/83461878762.pdf
    • https://cdn.shopify.com/s/files/1/0428/5317/1356/files/29911627597.pdf
    • https://cdn.shopify.com/s/files/1/0437/9534/9661/files/sevilla_albeniz_piano.pdf
    • https://cdn.shopify.com/s/files/1/0431/2619/4342/files/maxixolugifiwobapawokuf.pdf
    • https://cdn.shopify.com/s/files/1/0437/8063/6821/files/70839359917.pdf
    • https://cdn.shopify.com/s/files/1/0437/6104/1559/files/public_infrastructure_asset_management.pdf
    • https://cdn.shopify.com/s/files/1/0427/7973/8278/files/60648945739.pdf
    • https://cdn.shopify.com/s/files/1/0434/7763/1126/files/85968744064.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_off00006b61.bin
2f6874548289dbc1a7dffdd2a722bdb48e419bbf97a3f67ca35b989c995ea476
pdf-font-stream PDF embedded font (sfnt) at offset 0x6B61 5044 bytes
font_01_sfnt_off00007c86.bin
5b34098230f07f561053c42f75425331a083a56325ae31683830896d9e767e9e
pdf-font-stream PDF embedded font (sfnt) at offset 0x7C86 15832 bytes