Malicious PDF — malware analysis report

Static analysis result for SHA-256 9e60a094544a7d0d…

MALICIOUS

PDF

44.8 KB Created: 2020-09-03 08:39:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cf90bc586c3f2d4799305628fc0b0f74 SHA-1: c3cb9a486b4ba002f539e16f8d827bfd126de902 SHA-256: 9e60a094544a7d0d7837ea04b1f386f30328c9e11d93bf6c30c373e990c2c3b1
152 Risk Score

Malware Insights

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

The PDF contains a link that redirects to a known malicious domain, disguised as a resource for interview questions. The PDF also functions as a link farm, pointing to numerous other PDFs hosted on static.usrfiles.com, likely to manipulate search engine results or distribute further malicious content. The ML classifier strongly indicated maliciousness.

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.link/wix?keyword=100+most+difficult+interview+questions+and+answers
    • https://static.usrfiles.com/ugd/b0cd75_23ea84ee19824ac889af7fb30962b2ef.pdf
    • https://static.usrfiles.com/ugd/590778_6f67a87cdd504e61a07d3917097c4e12.pdf
    • https://static.usrfiles.com/ugd/b8c837_affdca35539d4e3f84b75cf182a391b1.pdf
    • https://static.usrfiles.com/ugd/dfb5f8_1e6aa389917748128ade646dbb6125eb.pdf
    • https://static.usrfiles.com/ugd/ddb60a_cdbac9b87b714fd9aac9dbcb2515793b.pdf
    • https://static.usrfiles.com/ugd/4d6844_59bb1f1b1e80434aafd244cfaef10b06.pdf
    • https://static.usrfiles.com/ugd/b8c837_714e8b6834044b54b35d2edd40928b03.pdf
    • https://cdn.shopify.com/s/files/1/0430/3863/8241/files/pimuwo.pdf
    • https://cdn.shopify.com/s/files/1/0435/8130/9085/files/idp_ielts_date_in_nepal_2019.pdf
    • https://cdn.shopify.com/s/files/1/0431/5702/9019/files/xuvopikinaxipadikuxiran.pdf
    • https://cdn.shopify.com/s/files/1/0437/8954/9729/files/top_reader_linux.pdf
    • https://cdn.shopify.com/s/files/1/0436/0349/3028/files/xunibumede.pdf
    • https://static.usrfiles.com/ugd/b8c837_3bfb702965b1477b80a3483ce8996ab9.pdf
    • https://static.usrfiles.com/ugd/e5cbe5_962173899249412797c69cf040bdc970.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_off0000704d.bin
5ed4283fcc23ce57aded4b761d7a7961497734abb76d4ce181ad45b2e77c2643
pdf-font-stream PDF embedded font (sfnt) at offset 0x704D 5544 bytes
font_01_sfnt_off00008328.bin
fd37d37b18151392d810d51e3b590776d824bce16d2ed5d8b84fdb7360467340
pdf-font-stream PDF embedded font (sfnt) at offset 0x8328 10192 bytes