Malicious PDF — malware analysis report

Static analysis result for SHA-256 8790ccac892ed2ae…

MALICIOUS

PDF

39.1 KB Created: 2020-07-31 12:20:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 16ed7d90e0d5dce04aa97080539ee9ae SHA-1: a0ef01fe743f656c10936acd0aeb274fc110e5ec SHA-256: 8790ccac892ed2ae91aaa8266d113f5e8c41b2d6eae1c0834c91c2335b907ba7
152 Risk Score

Malware Insights

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

The PDF file contains numerous embedded links, with a critical heuristic firing indicating a link to known malicious redirector infrastructure. The ML classifier also strongly flagged this PDF as malicious. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool sometimes used to create malicious PDFs. The primary attack vector appears to be luring users to click on malicious links within the document.

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.cc/pify?keyword=connect+4+shots+instructions+pdf
    • http://files.1210photography.com/uploads/1/3/2/7/132740900/1579119.pdf
    • http://files.opunakesurflifesaving.com/uploads/1/3/0/8/130814513/gezitowejukejekojuko.pdf
    • http://files.kitimatsnowvalleyskatingclub.com/uploads/1/3/0/9/130969700/duralodeg_remujevizokaw_lidobun.pdf
    • https://cdn.shopify.com/s/files/1/0431/5827/4205/files/pivukakotimexe.pdf
    • https://cdn.shopify.com/s/files/1/0433/4098/8575/files/komagobinuse.pdf
    • https://cdn.shopify.com/s/files/1/0432/0762/2817/files/voputubumimum.pdf
    • https://cdn.shopify.com/s/files/1/0428/7230/7875/files/27396872350.pdf
    • https://cdn.shopify.com/s/files/1/0433/0281/3849/files/55339415632.pdf
    • https://cdn.shopify.com/s/files/1/0435/6970/9217/files/xudipajabosubigijel.pdf
    • https://cdn.shopify.com/s/files/1/0429/3787/6639/files/50002890350.pdf
    • https://cdn.shopify.com/s/files/1/0431/4929/5776/files/17705061883.pdf
    • https://cdn.shopify.com/s/files/1/0431/1983/7346/files/logugaxajuxobunopawup.pdf
    • https://cdn.shopify.com/s/files/1/0440/7348/4438/files/68513102196.pdf
    • https://cdn.shopify.com/s/files/1/0435/4713/2068/files/42065978724.pdf
    • https://cdn.shopify.com/s/files/1/0431/7272/4885/files/61217950814.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/
    • https://cdn.shopify.com/s/files/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00005c8c.bin
4c1f87b6e1730e44a1ac4485de7f807d0931eb490a567b709961223e3793cf36
pdf-font-stream PDF embedded font (sfnt) at offset 0x5C8C 4992 bytes
font_01_sfnt_off00006d84.bin
4730e83b9ac937f701327faaa931a73fc928fc8c9695fc0f4cad94636e9c3bfa
pdf-font-stream PDF embedded font (sfnt) at offset 0x6D84 9964 bytes