Malicious PDF — malware analysis report

Static analysis result for SHA-256 2ae51d8d62a89b74…

MALICIOUS

PDF

31.0 KB Created: 2020-08-31 16:25:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 32db4fa5e3577625687a532cb4602a60 SHA-1: e86c3c85ff76cf574f2a548027dc646f9c635a36 SHA-256: 2ae51d8d62a89b74f1266a8b475149bb0ba4944b0045c24b16c63d32356b876d
152 Risk Score

Malware Insights

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

The PDF document was identified as malicious by an ML classifier and contains a link farm with 12 external PDF links. One of these links, https://ttraff.ru/wix?keyword=thk+3d+cad+models, points to known malicious redirector infrastructure. The document body contains garbled text and the authoring application is wkhtmltopdf, suggesting it was programmatically generated to host these links.

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=thk+3d+cad+models
    • https://static.usrfiles.com/ugd/1decf9_55cec78d71124505a7dd8260f8c76fe5.pdf
    • https://static.usrfiles.com/ugd/0f5b72_59294b4d13fb4789892affb199d54e3f.pdf
    • https://static.usrfiles.com/ugd/544c7e_dc0dfcf2b9744ba0b0c1835b5e0ce01f.pdf
    • https://cdn.shopify.com/s/files/1/0434/2461/2509/files/youtube_topic_music.pdf
    • https://cdn.shopify.com/s/files/1/0459/2805/4951/files/cretsiz_aptoide_indir_apk.pdf
    • https://cdn.shopify.com/s/files/1/0432/7669/7760/files/iata_city_code_list.pdf
    • https://cdn.shopify.com/s/files/1/0432/8180/9563/files/chicago_bears_colors_paint.pdf
    • https://cdn.shopify.com/s/files/1/0430/2965/9805/files/nisenifepuda.pdf
    • https://cdn.shopify.com/s/files/1/0468/8130/8829/files/sucursais_de_santaniana.pdf
    • https://cdn.shopify.com/s/files/1/0462/2142/6841/files/zugifidun.pdf
    • https://cdn.shopify.com/s/files/1/0440/3891/4213/files/85153135743.pdf
    • https://cdn.shopify.com/s/files/1/0432/3383/7224/files/bissell_powersteamer_powerbrush_manual.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_off00003d91.bin
1395f22e162f03da93caec876ee03491038942a4a1039021918875b5c880986b
pdf-font-stream PDF embedded font (sfnt) at offset 0x3D91 5260 bytes
font_01_sfnt_off00004f4b.bin
55c84ff7a15c7de062da12e9620155373bc449d1721df90f0585dc8539c2a5c4
pdf-font-stream PDF embedded font (sfnt) at offset 0x4F4B 9608 bytes