Malicious PDF — malware analysis report

Static analysis result for SHA-256 4321bd7a3c7927d8…

MALICIOUS

PDF

37.3 KB Created: 2020-08-30 02:43:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1ff6fd1689eaede46ad6cce483448028 SHA-1: 966ef3a759bf2b8d9298cb8c22b80c5292e4dc65 SHA-256: 4321bd7a3c7927d8550b86d151b8572a9d5d2d6b4978b010286601340cb66d5c
154 Risk Score

Malware Insights

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

The PDF contains multiple embedded links, with one specifically identified as a malicious redirector. The document body, though heavily obfuscated, contains text related to a book title and the authoring application 'wkhtmltopdf', suggesting a lure. The primary malicious IOC is the redirector URL, which is likely used to funnel users to further malicious content. The presence of numerous links, many pointing to seemingly benign PDF files, indicates a link farm or SEO poisoning tactic.

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.me/wix?keyword=diary+of+an+oxygen+thief+book+read+online+free
    • https://static.usrfiles.com/ugd/b8c837_f51b578cdb8a458c946aa13a31110476.pdf
    • https://static.usrfiles.com/ugd/f14cf6_0616b04ef1d74cb1b8147c30d8b4ad37.pdf
    • https://static.usrfiles.com/ugd/b8c837_fb7fc2dae14e4569b8b42b5c837cbf2d.pdf
    • https://cdn.shopify.com/s/files/1/0430/7773/0464/files/rational_and_irrational_worksheet.pdf
    • https://cdn.shopify.com/s/files/1/0447/3402/1788/files/miller_applied_asymptotic_analysis.pdf
    • https://cdn.shopify.com/s/files/1/0430/2677/6227/files/kixapevekuvugabepes.pdf
    • https://cdn.shopify.com/s/files/1/0438/6396/5861/files/55063382978.pdf
    • https://static.usrfiles.com/ugd/cd79e3_bab430ff66774af9882ec50f51ced658.pdf
    • https://static.usrfiles.com/ugd/409ca8_0ac9a8bb7cce4d37881dd41571c1e92a.pdf
    • https://static.usrfiles.com/ugd/b8c837_8e7c60119e7a47c4bb0677d44fedcb88.pdf
    • https://static.usrfiles.com/ugd/05900a_5331da84c52c4add959a72d53a5484c2.pdf
    • https://static.usrfiles.com/ugd/b8c837_62791ce8fa0e495aa54d24cf65722194.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000474b.bin
be385f830974960af5a1ba7b3b67e920beae09ab4102144b34d3e14cd5b79b39
pdf-font-stream PDF embedded font (sfnt) at offset 0x474B 5152 bytes
font_01_sfnt_off000058cf.bin
8f1219b9fa5bb589e97fc425e752307a7d51793d4db7ed6aff99d0c83962157b
pdf-font-stream PDF embedded font (sfnt) at offset 0x58CF 9788 bytes
font_02_sfnt_off00007a52.bin
b50a2106bf82917db0cd3cf88f63c5e8cc3298b343ace5cffc591b35df33d24c
pdf-font-stream PDF embedded font (sfnt) at offset 0x7A52 4324 bytes