Malicious PDF — malware analysis report

Static analysis result for SHA-256 e536a2835274f386…

MALICIOUS

PDF

47.4 KB Created: 2020-08-31 07:17:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0f297eb5b2a2c5ab94492baee9ecb42b SHA-1: 2cdfbd2a637ce55eafc6ef4bba3c9b3ba935ee56 SHA-256: e536a2835274f3862f8f5ceec13058d8076e89bfb5c1c58ddb78918e0c018a03
152 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by an ML classifier and contains a critical heuristic indicating it links to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains the URL that triggered the redirector heuristic. The file also exhibits characteristics of a PDF link farm, with numerous embedded URLs pointing to external PDF documents, likely an attempt to manipulate search engine rankings or distribute further malicious content.

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=sistema+de+ecuaciones+lineales+inconsistente
    • https://static.usrfiles.com/ugd/ca300b_edb402fe7f76471585ff8bd65715ad39.pdf
    • https://static.usrfiles.com/ugd/b8c837_e90bf73675f04c30b8fc7ed03ca40738.pdf
    • https://static.usrfiles.com/ugd/e3c460_43e28661806c4b00baa0a5d01a096f90.pdf
    • https://cdn.shopify.com/s/files/1/0431/5817/5906/files/biology_advanced_level_notes.pdf
    • https://cdn.shopify.com/s/files/1/0447/2560/0410/files/how_to_thread_a_kenmore_sewing_machine.pdf
    • https://static.usrfiles.com/ugd/b8c837_f0ebfcabce4c4cf0a162a5a8fcf1f344.pdf
    • https://static.usrfiles.com/ugd/b8c837_370c8a4cf64e465498425d509cdb1949.pdf
    • https://static.usrfiles.com/ugd/89363e_803966f4b0e443b58ae343366be89210.pdf
    • https://cdn.shopify.com/s/files/1/0428/8308/8547/files/19427000857.pdf
    • https://cdn.shopify.com/s/files/1/0436/0624/5539/files/algebra_1_problems.pdf
    • https://cdn.shopify.com/s/files/1/0428/9714/6019/files/40868480905.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_off0000796d.bin
6ff27430caf9350385a172cfdf9017435dd24412d59a17e18fb4f8c05ad255d1
pdf-font-stream PDF embedded font (sfnt) at offset 0x796D 5092 bytes
font_01_sfnt_off00008a9a.bin
b5c81b1b2e23da93fb80aee04ae07ac7409c32bad1072beb97b9bcbb216633da
pdf-font-stream PDF embedded font (sfnt) at offset 0x8A9A 11728 bytes