Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c40a191500fca35…

MALICIOUS

PDF

42.0 KB Created: 2020-08-23 06:53:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 5a4a8ddff48f6dff283d4568557e63dd SHA-1: ea4440fbedae3b4758d85b4e47a087fe1fe15c1d SHA-256: 5c40a191500fca35cf128bd11df8d3110c1404a9f8a6ef8fd0cb73d7e3600bba
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains embedded links that lead to a redirector service, which in turn points to a collection of other PDFs. This behavior is indicative of a link farm used to obscure malicious destinations or to distribute further malicious content. The ML classifier also strongly flagged this PDF as malicious. No scripts were extracted, but the embedded links are the primary mechanism for the attack.

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.com/pify?keyword=openwrt+archer+c7+v4
    • http://kimapaxup.bbt-livonia.com/uploads/1/3/2/3/132303354/18d0dca34.pdf
    • http://takidu.commemorativechoir.com/uploads/1/3/1/4/131406086/7312481.pdf
    • http://zuruwed.africaglobalmedia.net/uploads/1/3/1/8/131871825/4702908.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0428/7922/1927/files/40617973512.pdf
    • https://cdn.shopify.com/s/files/1/0431/3910/4917/files/vosuvovutevoviruzedu.pdf
    • https://cdn.shopify.com/s/files/1/0437/7654/0834/files/38995882923.pdf
    • https://cdn.shopify.com/s/files/1/0428/9147/7159/files/62399905169.pdf
    • https://cdn.shopify.com/s/files/1/0452/8783/3762/files/verazawotilonuxupa.pdf
    • https://cdn.shopify.com/s/files/1/0450/1287/7462/files/remijifeniziw.pdf
    • https://cdn.shopify.com/s/files/1/0427/3415/7991/files/69434952624.pdf
    • https://cdn.shopify.com/s/files/1/0436/3884/9694/files/radada.pdf
    • https://cdn.shopify.com/s/files/1/0440/7099/4085/files/5431962222.pdf
    • https://cdn.shopify.com/s/files/1/0431/3042/1410/files/86431809012.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/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006516.bin
f018bf1fd36174ebaa4b2928645f0845db8cc0ef199bad2bdd7986291c9c1cc6
pdf-font-stream PDF embedded font (sfnt) at offset 0x6516 5156 bytes
font_01_sfnt_off000076b4.bin
e807b8bded19440518bc6521a5964b1b29113bd698485b20d68e5f454dd4b04c
pdf-font-stream PDF embedded font (sfnt) at offset 0x76B4 10968 bytes