Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b845d66d5fd330e…

MALICIOUS

PDF

39.3 KB Created: 2020-09-10 14:40:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 3403526b119ca4768922523a6fd0f1ee SHA-1: 318f61bb63f0bb28a8b8976e601d3979043aea0f SHA-256: 3b845d66d5fd330e21125333239350ee0f1929241047bfed139b9d8f68e4e08a
152 Risk Score

Malware Insights

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

The PDF contains a link that redirects to known malicious infrastructure, as indicated by the PDF_MALICIOUS_REDIRECTOR_LINK heuristic. The document body, though heavily obfuscated, contains text that appears to be a lure related to 'answer to all math problems' and includes the malicious URL. The PDF_SEO_LINK_FARM heuristic also indicates the presence of numerous external links, suggesting a broader campaign to distribute 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.link/pify?keyword=answer+to+all+math+problems
    • http://files.bluenosewoodworks.com/uploads/1/3/2/8/132815961/somokirolurujewikusi.pdf
    • http://files.jaramilyn.com/uploads/1/3/1/4/131437005/jixorozuge-wukekijodulavuj-sifetojadug-vonesupakinalel.pdf
    • http://files.francislewisenglish.com/uploads/1/3/1/8/131856917/maruxegoweko.pdf
    • https://static.usrfiles.com/ugd/451a43_bd8e02a2b69841798162b30f1d00f663.pdf
    • https://static.usrfiles.com/ugd/22bf55_87560e2944f14226a918e12a18a7f8b1.pdf
    • https://static.usrfiles.com/ugd/b8c837_eef65faab57c451da30947b4172d077f.pdf
    • https://cdn.shopify.com/s/files/1/0431/6430/3516/files/88016809691.pdf
    • https://cdn.shopify.com/s/files/1/0440/7423/8102/files/81047224961.pdf
    • https://static.usrfiles.com/ugd/1c8c6c_9c5234e77ee34b4ea40f0f4f36b520b8.pdf
    • https://static.usrfiles.com/ugd/40b9e6_aa977192b5d5468bb2ee81c6bf433885.pdf
    • https://static.usrfiles.com/ugd/f09a9d_3924a539a7a5436aa53d9e2ce09f0f37.pdf
    • https://static.usrfiles.com/ugd/66c878_81b308ecb3864d9f82431b66cc7ecb1e.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_off0000512b.bin
2c1c3e11700de74eb1ca9625c712a0b5b7ce3c75d355bd87e82a2771ed2c2e56
pdf-font-stream PDF embedded font (sfnt) at offset 0x512B 5020 bytes
font_01_sfnt_off0000620f.bin
000597a554babdf34c7b7a45c9adbca3ca7805b849ded090bf85cef51c670ae1
pdf-font-stream PDF embedded font (sfnt) at offset 0x620F 9632 bytes
font_02_sfnt_off000082d6.bin
ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3
pdf-font-stream PDF embedded font (sfnt) at offset 0x82D6 4324 bytes