Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4b8f33bc2cef282…

MALICIOUS

PDF

46.7 KB Created: 2020-08-06 22:20:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e34419ba1c6a8f6ae507e602093b1718 SHA-1: cf03bb337f61c5464fb81e5f4846c1b6ae191346 SHA-256: a4b8f33bc2cef282482296f0e6b9b1bec7ed66c4ec19c87b0e41fece0c2bba12
154 Risk Score

Malware Insights

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

The PDF document contains a large number of embedded links, with a critical heuristic firing indicating a malicious redirector. The document body and embedded links suggest an attempt to lure users to malicious sites, potentially for phishing or malware distribution. The ML classifier strongly supports the malicious verdict.

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/wb?keyword=exsultet%20latin%20pdf
    • http://files.gulnurozdaglar.com/uploads/1/3/2/3/132302913/38e83.pdf
    • http://files.alltiedupstocktie.com/uploads/1/3/1/4/131452806/zakozuwajumaduso.pdf
    • http://files.jennsutkowski.com/uploads/1/3/0/9/130968942/gimodoniwafote_sepurumuzidu_wakusa.pdf
    • http://files.arkansasbasin.com/uploads/1/3/1/3/131380005/kutibezoxikorop_waganag_wuvejaxoleluse_nuwavifotik.pdf
    • http://files.the-westwood-wire.info/uploads/1/3/1/4/131437254/8942002.pdf
    • https://cdn.shopify.com/s/files/1/0429/4773/9811/files/99958465920.pdf
    • https://cdn.shopify.com/s/files/1/0427/7259/4844/files/50427008557.pdf
    • https://cdn.shopify.com/s/files/1/0433/1785/4373/files/tewazefoxoxalatewu.pdf
    • https://cdn.shopify.com/s/files/1/0437/3646/5559/files/aggrieved_meaning_in_telugu.pdf
    • https://cdn.shopify.com/s/files/1/0433/3387/7914/files/metejebe.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/lonuxifipepi.pdf
    • https://cdn.shopify.com/s/files/1/0431/9353/2573/files/86834687663.pdf
    • https://cdn.shopify.com/s/files/1/0430/9339/3557/files/18607981202.pdf
    • https://cdn.shopify.com/s/files/1/0431/6702/3259/files/8926310203.pdf
    • https://cdn.shopify.com/s/files/1/0428/8849/5270/files/burda_magazine_free.pdf
    • https://cdn.shopify.com/s/files/1/0432/6703/1200/files/vizudesajesafosadebeme.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_off00007aca.bin
d4133d6056de8620f7546b51940e8bb7c9e621cd7a3c7cc44d451c326d810a10
pdf-font-stream PDF embedded font (sfnt) at offset 0x7ACA 4964 bytes
font_01_sfnt_off00008bcb.bin
455f67e55acfbd9eb4c60e39d1c0b012278ced98e596249d258fcbeacf792db6
pdf-font-stream PDF embedded font (sfnt) at offset 0x8BCB 9992 bytes