Malicious PDF — malware analysis report

Static analysis result for SHA-256 75adc11d2b288cf4…

MALICIOUS

PDF

39.5 KB Created: 2020-08-31 02:51:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ef1ac809d5f43058cbe57e2953887c40 SHA-1: 7e75144dac1372558a72a786a51488c8832b4a17 SHA-256: 75adc11d2b288cf40b9d6af6b4e3c9f4ab26733a47dbba428091d518a6f4d76d
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains embedded links that redirect to a known malicious domain, identified by the PDF_MALICIOUS_REDIRECTOR_LINK heuristic. The document body, though partially garbled, suggests a lure related to an academic worksheet. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous external links indicates a potential SEO link farm or content-spinning operation designed to attract victims.

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/wix?keyword=kayarian+ng+pang-+uri+worksheet+grad
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/b8c837_25d5a4b562784fd4b839be6dde1cb774.pdf
    • https://static.usrfiles.com/ugd/3b7182_35a790871308483d83a0b700cd567ab4.pdf
    • https://static.usrfiles.com/ugd/de3d83_e274cf3155c640319d364a0e8904c41d.pdf
    • https://static.usrfiles.com/ugd/f459ea_90e93c83308440d3a1e4e32e76f8057e.pdf
    • https://static.usrfiles.com/ugd/6c98bc_04b5b17bf6ec491ba8da28e4788dd5d5.pdf
    • https://static.usrfiles.com/ugd/73f3b0_0c433cec5ce24220b0dcdca07f1acfbe.pdf
    • https://static.usrfiles.com/ugd/37428b_40e9432a3869481ca713aebd46b1b170.pdf
    • https://static.usrfiles.com/ugd/f63f29_8f6cfab21f954f01b549bdb381742479.pdf
    • https://static.usrfiles.com/ugd/cfbfd2_aec250eb07824c0599152db63e835f3b.pdf
    • https://static.usrfiles.com/ugd/b8c837_89ca5d07582545b3a6e3f7cf3843dbbc.pdf
    • https://static.usrfiles.com/ugd/bfbc46_bf7b2416cf784ad08d785647d9775cbe.pdf
    • https://static.usrfiles.com/ugd/0511f5_33b8c1ccb9fd4650a0524ab3809bc397.pdf
    • https://static.usrfiles.com/ugd/02beb7_7a802cdb624a4c699d894957d01351aa.pdf
    • https://static.usrfiles.com/ugd/a01749_218e11ecfaac4cb3ba4baee1dd7fa655.pdf
    • https://static.usrfiles.com/ugd/5cf23b_424920fa869a465e8099f8fc171bb875.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005e22.bin
08702f1cea51ed1a04f642844432c9357f5f563313bc69a3ff6e76d6936ca136
pdf-font-stream PDF embedded font (sfnt) at offset 0x5E22 5448 bytes
font_01_sfnt_off000070be.bin
ee7c4f33f5191d7dd5b8218b6a0efdcb832c6cfe9d6b54373d74d123438f1301
pdf-font-stream PDF embedded font (sfnt) at offset 0x70BE 9496 bytes