Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac84f636bd6d82a3…

MALICIOUS

PDF

40.7 KB Created: 2020-09-05 06:53:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2f3b88abc30a9a61e2d4eed1dbd635db SHA-1: 4c15079303526b709efd210ef0e73ca5325d7edb SHA-256: ac84f636bd6d82a343573f9f480fb88507d9f0627896df26dc5b5afc4d08512c
152 Risk Score

Malware Insights

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

The PDF contains multiple embedded links, with one specifically pointing to a known malicious redirector. The document body, though heavily obfuscated, contains the string 'https://ttraff.link/wix?keyword=astral+form+bfa', indicating a lure to a malicious site. The presence of numerous links to external PDFs, many hosted on static.usrfiles.com, suggests a link farm designed to distribute further malicious content or engage in SEO manipulation for malicious purposes.

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=astral+form+bfa
    • https://static.usrfiles.com/ugd/9219f8_225086d17f7045cba02e4261026a4daa.pdf
    • https://static.usrfiles.com/ugd/d7c203_d3c6d15415e543d594b5f3e1764daa5f.pdf
    • https://static.usrfiles.com/ugd/dcbeda_5e8502977a634e368e04e49e44be4e7f.pdf
    • https://static.usrfiles.com/ugd/8d57bd_6fa610c340c1465db1bc6e83df09f554.pdf
    • https://static.usrfiles.com/ugd/bfbc46_8cfc2681bd1a4fc38d0c3f11ffdd2dd7.pdf
    • https://static.usrfiles.com/ugd/436160_24e2fe7d7d3c44b2811b047adde9d56f.pdf
    • https://static.usrfiles.com/ugd/b8c837_78b162e72da3437086b193559b6a6bf9.pdf
    • https://static.usrfiles.com/ugd/0c4177_e6e99241a05f4795b061286829f1c716.pdf
    • https://static.usrfiles.com/ugd/3b7182_b26d8ab209034e8dbe984ed62a0bc623.pdf
    • https://static.usrfiles.com/ugd/f46427_e1a850934b844abbbb3e5e6e47c7d010.pdf
    • https://static.usrfiles.com/ugd/a298ce_e396d49fbf234ba89e3815f0978af696.pdf
    • https://static.usrfiles.com/ugd/7ff653_67bb3ccd72ef4d6a945c410b2a55dc8c.pdf
    • https://static.usrfiles.com/ugd/b8c837_d4f0c95c0cfc47c3ad749529c535000e.pdf
    • https://static.usrfiles.com/ugd/185811_98fe4a0756814e008a9947a71b05a1fa.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_off0000622b.bin
d82189ecdfe8713166d0d968f7a175fdf1528c7218d81c8cb725fb375d8a028c
pdf-font-stream PDF embedded font (sfnt) at offset 0x622B 5040 bytes
font_01_sfnt_off00007339.bin
724a141e156184739f5e98dee073cb3e5a2bc52f91ffdc37f0477720dfca7fdd
pdf-font-stream PDF embedded font (sfnt) at offset 0x7339 10340 bytes