Malicious PDF — malware analysis report

Static analysis result for SHA-256 221801e2aa5fdb52…

MALICIOUS

PDF

67.6 KB Authoring application: PDF Studio First seen: 2020-09-24
MD5: c6b9df640e573d70d74b525080e20083 SHA-1: 1dcf11058e038d45123931f790a1f09cd27bc768 SHA-256: 221801e2aa5fdb527f29b6693dfe95e3bf6496c97f6d39612950682bf17dc581
172 Risk Score

Malware Insights

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

The PDF was flagged by multiple heuristics, including ClamAV and an ML classifier, as malicious. The PDF_SEO_LINK_FARM heuristic indicates a large number of embedded external links, with the first identified URL being http://kwcrsupport.com/uploads/1/3/0/2/130291544/bederu.pdf. This suggests the document's primary purpose is to act as a lure, directing users to potentially malicious content hosted on external domains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

Heuristics 4

  • ClamAV: Pdf.Phishing.TtraffRobotInstall-7605656-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.TtraffRobotInstall-7605656-0
  • 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.
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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 http://kwcrsupport.com/uploads/1/3/0/2/130291544/bederu.pdf In PDF document text
    • http://doceinstein.com/uploads/1/3/0/4/130435499/kunasatulenaluguzow.pdfIn PDF document text
    • http://kav.amazon-sellers-check.com/uploads/2020/01/29/2f849f.pdfIn PDF document text
    • http://windswept.co.za/uploads/1/3/0/5/130550876/130550876.html#kubrow+lotus+patternIn PDF document text
    • https://savannah.gnu.org/projects/freefont/In PDF document text
    • http://www.gnu.org/licenses/In PDF document text
    • http://www.gnu.org/copyleft/gpl.htmlIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000011c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C9 8956 bytes
SHA-256: 319b5782ebf85ed615dc5abcbe67d5cc31cf4a979139c08af06f81c2f4611105
font_01_sfnt_off0000b0a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0A7 7752 bytes
SHA-256: e0d98453bb794b955f45aabe8bffa13c644e060e6e51debb9330bb5abff60781
font_02_sfnt_off0000c422.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC422 16040 bytes
SHA-256: de9ab7d3f801febf349f8627b7aa0c20fcf05f39190c656d73ff63bae9e1d702