Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4b8ab31b0f92d92…

MALICIOUS

PDF

39.4 KB Created: 2020-08-15 03:34:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1ccd11095b0c93fed605c34f7e95d893 SHA-1: d0a474adb762a5f66d52e3c30eb120c12075c8b1 SHA-256: a4b8ab31b0f92d92bbfa220c8119fe601fca74e106dd0271cf84ce6568c987d5
154 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for a malicious redirector link, pointing to ttraff.ru. The document body, though heavily obfuscated, contains the same URL and appears to be a lure disguised as an installation manual. The PDF also exhibits characteristics of a link farm, with numerous embedded URLs pointing to external PDF files, some of which are hosted on potentially compromised domains. The ML classifier strongly indicates maliciousness.

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/wb?keyword=insinkerator%20evolution%20pro%20compact%20installation%20manual
    • http://files.massagetherapyvt.com/uploads/1/3/0/7/130776460/menawu.pdf
    • http://files.yingyanzhao.com/uploads/1/3/1/4/131437724/riwuwefurosan_vorijemud.pdf
    • http://files.brandongillin.com/uploads/1/3/1/8/131856347/e4de509a6.pdf
    • https://cdn.shopify.com/s/files/1/0451/3919/8105/files/introduction_of_web_designing.pdf
    • https://cdn.shopify.com/s/files/1/0444/2639/5814/files/tv_tropes_gargoyles.pdf
    • https://cdn.shopify.com/s/files/1/0429/5429/3402/files/bogafapirulowebelawogum.pdf
    • https://cdn.shopify.com/s/files/1/0436/7374/7609/files/botewugabilodozuforoziz.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/varanomavumozomadeda.pdf
    • https://cdn.shopify.com/s/files/1/0431/2875/0241/files/92083730122.pdf
    • https://cdn.shopify.com/s/files/1/0427/8976/5279/files/wubokoxupofuvegewoxa.pdf
    • https://cdn.shopify.com/s/files/1/0439/8222/5566/files/que_es_administrador_de_dispositivos_en_informatica.pdf
    • https://cdn.shopify.com/s/files/1/0431/7547/7407/files/37045947070.pdf
    • https://cdn.shopify.com/s/files/1/0434/0131/4456/files/fixuduvowetufazepig.pdf
    • https://cdn.shopify.com/s/files/1/0434/3624/5142/files/full_program_indir.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_off00005c34.bin
dcd4fca45025d9f05dbd130d61f590f34196e9479bde0da0852f3a59c512407b
pdf-font-stream PDF embedded font (sfnt) at offset 0x5C34 5140 bytes
font_01_sfnt_off00006d99.bin
d0155508f5f24a276db9d47069dd8c78fd5c1346ae328266462aea8f261c51a6
pdf-font-stream PDF embedded font (sfnt) at offset 0x6D99 10244 bytes