Malicious PDF — malware analysis report

Static analysis result for SHA-256 2a8f8ba1a4769779…

MALICIOUS

PDF

47.5 KB Created: 2020-08-29 06:22:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 35a868bc848b56d11ea657c48ddd28f1 SHA-1: 79aa33d832538181e263a8a19a773a568f2798aa SHA-256: 2a8f8ba1a47697793a1efdedb693191d8149df0478310440e1551094d5e481c0
152 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for a malicious redirector link, pointing to a URL that mimics a free streaming service. This URL is presented within the document body, suggesting a social engineering tactic to trick users into clicking. The presence of numerous external links, many pointing to benign-looking PDFs hosted on static.usrfiles.com, indicates a link farm strategy, likely to improve search engine ranking or distribute traffic. 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.cc/wix?keyword=watch+trolls+online+free+megashare
    • https://static.usrfiles.com/ugd/b8c837_dfb3f0fb8f694c62ba1aebb548656911.pdf
    • https://static.usrfiles.com/ugd/b8c837_07946f6620f94690a33f122be990c259.pdf
    • https://static.usrfiles.com/ugd/b8c837_2734c83abdf44af1a55532e2184037fa.pdf
    • https://static.usrfiles.com/ugd/b8c837_82eff5da619c43febc61b3dbc129ae41.pdf
    • https://cdn.shopify.com/s/files/1/0429/7218/4732/files/70453606716.pdf
    • https://cdn.shopify.com/s/files/1/0438/4561/5766/files/dobajojizunijiwutako.pdf
    • https://cdn.shopify.com/s/files/1/0437/3364/7525/files/fevumasokateputokimiwe.pdf
    • https://cdn.shopify.com/s/files/1/0431/6259/9584/files/26670765535.pdf
    • https://cdn.shopify.com/s/files/1/0432/2741/4696/files/types_of_inorganic_compounds.pdf
    • https://static.usrfiles.com/ugd/b8c837_63f930eeefe54607b2a09fbba739838f.pdf
    • https://static.usrfiles.com/ugd/b8c837_2add61c2764c44468a3083442cb4b740.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000065c2.bin
b2fe3169eb5ca2ae9b85b1606fbf4f858dddd319cf71e42c7fec25f658ff4f6f
pdf-font-stream PDF embedded font (sfnt) at offset 0x65C2 5308 bytes
font_01_sfnt_off000077ad.bin
ab016e586e918ffa31491c6f517bd46ee546033ce4246cc71a737417586de0ec
pdf-font-stream PDF embedded font (sfnt) at offset 0x77AD 10608 bytes
font_02_sfnt_off00009c38.bin
467334b253c03183b8f59c8c7859f446a4d85e3bd71546e4bc7697603d08a064
pdf-font-stream PDF embedded font (sfnt) at offset 0x9C38 16120 bytes