Malicious PDF — malware analysis report

Static analysis result for SHA-256 7735a831b13cf9bb…

MALICIOUS

PDF

63.9 KB Created: 2020-08-31 07:24:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1b11925046c14404f570014a0c241c31 SHA-1: a03751fac1c3314824b5d22df3d7b5ea3ba97975 SHA-256: 7735a831b13cf9bb1289a8e024967b619b9c9315742b802ecca6411dec455348
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a significant number of embedded links to external PDF files, a technique often used for SEO manipulation or to distribute malicious content. One of these links, https://ttraff.me/wix?keyword=isentropic+efficiency+compressor+cal, is identified as a known malicious redirector. The ML classifier also strongly flagged this PDF as malicious. The document body appears to be malformed or heavily obfuscated, making it difficult to determine a specific user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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.me/wix?keyword=isentropic+efficiency+compressor+cal
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/b4a829_fe9ba97a235e4989a6d564789442b650.pdf
    • https://static.usrfiles.com/ugd/48f461_cbc16fc75a484e0896dedba466c80956.pdf
    • https://static.usrfiles.com/ugd/b8c837_ce4376c3d3a342f391a01856abd891d4.pdf
    • https://static.usrfiles.com/ugd/4b874d_39a2b0b0e2784176a748683723c542aa.pdf
    • https://cdn.shopify.com/s/files/1/0428/6034/7551/files/zuzulasur.pdf
    • https://cdn.shopify.com/s/files/1/0431/6869/4432/files/6085015773.pdf
    • https://cdn.shopify.com/s/files/1/0438/7287/8747/files/rikepimo.pdf
    • https://cdn.shopify.com/s/files/1/0431/3654/9018/files/a_very_potter_sequel.pdf
    • https://cdn.shopify.com/s/files/1/0451/1694/8633/files/81263064190.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
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00009c16.bin
1418c99550ed240a22464ee9e8b5978b6b81c1750ab4b57e6fb2348387d90187
pdf-font-stream PDF embedded font (sfnt) at offset 0x9C16 5200 bytes
font_01_sfnt_off0000adb2.bin
bf1cc7a26287eef866c84478e4bd6402bddc7fd9c3682768c9e77ec82f3d27b6
pdf-font-stream PDF embedded font (sfnt) at offset 0xADB2 15012 bytes
font_02_sfnt_off0000dcf2.bin
5010baaf93a2e71493c015c5db234a9b59a0566f4bc60eb3c337d781ad817604
pdf-font-stream PDF embedded font (sfnt) at offset 0xDCF2 16348 bytes