Malicious PDF — malware analysis report

Static analysis result for SHA-256 c7d53043f9ee1963…

MALICIOUS

PDF

52.4 KB Created: 2020-08-30 14:32:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 331dd2b1c15d8bb5503de1918fa914ab SHA-1: f78a80c98f5b3064dbd331eb025bf3ffb1a802ae SHA-256: c7d53043f9ee1963ea514b631d0d0215603aaaafbfe6ca2b11a0472902192723
152 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by a machine learning classifier and contains a critical heuristic indicating a link to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains the URL that triggered the redirector heuristic. The presence of numerous external PDF links, many pointing to static.usrfiles.com, suggests a link farm or SEO poisoning attempt to drive traffic to the malicious redirector.

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.ru/wix?keyword=adirondack+chair+templates+and+plan
    • https://static.usrfiles.com/ugd/80c1db_41f6cdcf52da41cd9c4c371ed35464ab.pdf
    • https://static.usrfiles.com/ugd/b8c837_953e6decbe2a445cbfe6efe51b00db57.pdf
    • https://static.usrfiles.com/ugd/b8c837_aed35aa1fc134d989308ae735df3f3d2.pdf
    • https://static.usrfiles.com/ugd/b8c837_7093ddc8f9744b2aac5c360e0eaceeec.pdf
    • https://static.usrfiles.com/ugd/b8c837_593548b0b5c1493f8bb286054310df6f.pdf
    • https://static.usrfiles.com/ugd/9f6a24_9b034ccbf0724b5eb7ebd2a9dcc4eb3b.pdf
    • https://static.usrfiles.com/ugd/dd4472_ce2db043f4dd4157815f36675b4ccfc9.pdf
    • https://static.usrfiles.com/ugd/b8c837_b8c3f96b8e13470b834a4425a36cae95.pdf
    • https://static.usrfiles.com/ugd/15cd4d_b74ca07592084ad8a75636956d5ecedf.pdf
    • https://static.usrfiles.com/ugd/90c678_5c68f02b909a43b293056341bc586036.pdf
    • https://static.usrfiles.com/ugd/b8c837_13a468482e48450dbbfc3fc476ab9681.pdf
    • https://static.usrfiles.com/ugd/6260fe_ec44d69057174baab3b3b52e68ea6ddc.pdf
    • https://static.usrfiles.com/ugd/0779a3_4cce20e344eb420a831b69f165081a26.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_off000089ea.bin
96953076addbc1602845c4a70e067b89a1b60fc0ecfe635a0067fe874cf87368
pdf-font-stream PDF embedded font (sfnt) at offset 0x89EA 5368 bytes
font_01_sfnt_off00009bf9.bin
cc58c2b94bae3feccbc0b3625c836e7300710ef1165bce3e3b54e616a5b65e0e
pdf-font-stream PDF embedded font (sfnt) at offset 0x9BF9 12772 bytes