Malicious PDF — malware analysis report

Static analysis result for SHA-256 cef5decd61501446…

MALICIOUS

PDF

43.0 KB Created: 2020-09-09 02:14:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 01785125bb727ab600180033601cb708 SHA-1: 0767c41f5a316a82619421416e3b6482e574037a SHA-256: cef5decd615014467568b9bfb8e75208b49406c9a8c87367b72f062a0d8b2408
150 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

This PDF file was flagged as malicious by a machine learning classifier and contains a critical heuristic indicating it links to known malicious redirector infrastructure. The document body, though partially corrupted, suggests a lure related to 'complete sentences worksheet'. The primary malicious IOC is the redirector URL, which is likely the entry point for a subsequent stage of the attack. The PDF also contains a large number of embedded links, many pointing to static.usrfiles.com, which is flagged as a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 3

  • 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.
  • 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=complete+sentences+worksheet
    • https://static.usrfiles.com/ugd/754d94_32d866c4b756433ea4e276099e66573e.pdf
    • https://static.usrfiles.com/ugd/9c0842_16d6f3b5b01c439da42d6d0e305aa453.pdf
    • https://static.usrfiles.com/ugd/ae15ca_d85fdb5c1db8453da7e85786d6169c80.pdf
    • https://static.usrfiles.com/ugd/b8c837_82e8055f5a22495692bf1ad55f98445c.pdf
    • https://static.usrfiles.com/ugd/0511f5_2eda70b209c743e3b0bb7f6115ac37a7.pdf
    • https://static.usrfiles.com/ugd/b4a829_aff57e61332f4e639eed239d5865fa96.pdf
    • https://static.usrfiles.com/ugd/8e1900_91111347833646c1b0effb27857ef9e9.pdf
    • https://static.usrfiles.com/ugd/b8c837_5f33da28321c406381cb980a03448b05.pdf
    • https://cdn.shopify.com/s/files/1/0465/2318/7350/files/centrelink_youth_allowance_form.pdf
    • https://cdn.shopify.com/s/files/1/0432/7807/4020/files/99690886376.pdf
    • https://cdn.shopify.com/s/files/1/0460/9556/4964/files/ledger_lines_worksheet_music.pdf
    • https://cdn.shopify.com/s/files/1/0431/7079/1573/files/67910117989.pdf
    • https://cdn.shopify.com/s/files/1/0428/9200/1433/files/acquisitions_incorporated_5e_download.pdf
    • https://cdn.shopify.com/s/files/1/0429/7113/6154/files/36772955597.pdf
    • https://cdn.shopify.com/s/files/1/0427/9291/1007/files/fogebibu.pdf
    • https://cdn.shopify.com/s/files/1/0463/3323/1266/files/amma_nanna_tamil_ammayi_songs_audio.pdf
    • https://cdn.shopify.com/s/files/1/0437/0087/9515/files/pdf_into_word.pdf
    • https://cdn.shopify.com/s/files/1/0432/9763/6512/files/befukejuvozi.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_off000069e3.bin
c75c1d1313d6437c2614b44149a97974746d2012d3e48c0c0c47715e8375ef82
pdf-font-stream PDF embedded font (sfnt) at offset 0x69E3 5024 bytes
font_01_sfnt_off00007ae2.bin
b2c2a1a8c020ed3da801d3bc665fc4995037b0a71ec04ac9b102e096b595ee3a
pdf-font-stream PDF embedded font (sfnt) at offset 0x7AE2 10412 bytes