Malicious PDF — malware analysis report

Static analysis result for SHA-256 141483b062699cf3…

MALICIOUS

PDF

45.3 KB Created: 2020-09-01 15:26:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 99d4ef6094dc3f65205070a31cce97cb SHA-1: 8d0f48ca3677353c9ada654b4919cba3760698cd SHA-256: 141483b062699cf3f4343d917e1c2889f22c7bd4ba9ad4b962828a1e7de627f7
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded links, many pointing to benign content, but one prominent link directs to a known malicious redirector. This suggests a tactic of SEO poisoning, where the PDF is disguised as a useful document to attract clicks to malicious infrastructure. The ML classifier also strongly indicated 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/wix?keyword=days+of+the+week+worksheet+for+preschool
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://static.usrfiles.com/ugd/7ef0dc_fb076d16bfd04aa78a8e016ccfa28e0f.pdf
    • https://static.usrfiles.com/ugd/67e251_0adfc765c6474cca9dec4ff5f992a99c.pdf
    • https://static.usrfiles.com/ugd/b8c837_502f1399816e44929536504239af61e2.pdf
    • https://static.usrfiles.com/ugd/b8c837_c81574f1bc3e4fe6a135adce403a74a5.pdf
    • https://static.usrfiles.com/ugd/b8c837_1120cf36c456447ea4535e950cd98174.pdf
    • https://static.usrfiles.com/ugd/50c35f_0caad3ecaad340658b63bc7fb6c5fe92.pdf
    • https://static.usrfiles.com/ugd/2c8d66_1954debf09b142dc9eb307b52dd53c49.pdf
    • https://static.usrfiles.com/ugd/0779a3_a7b5916a7cb642aaa2cd42dafa86f5e4.pdf
    • https://static.usrfiles.com/ugd/ab0441_88cd38a5b0dd44cba640c6ec0b4c0cd4.pdf
    • https://static.usrfiles.com/ugd/7ff653_ec0fdb3e1f354f388b5970a7c5c2268b.pdf
    • https://static.usrfiles.com/ugd/f103bb_baa163ec7c1349ed93f82d19e67235a3.pdf
    • https://static.usrfiles.com/ugd/b8c837_8841acee4a074effbb4820e0cae0aeb3.pdf
    • https://static.usrfiles.com/ugd/c7ef1a_7d02aaf10da24303a7fcbe45143464c3.pdf
    • https://static.usrfiles.com/ugd/ace02d_ceaffadb2eb540ecbe8e58ee0f2757eb.pdf
    • https://static.usrfiles.com/ugd/2f3ac6_8b65bed2484944339000d8becde2ad83.pdf
    • https://static.usrfiles.com/ugd/4117a9_f455a413489442b8b290cd3c47e60a01.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_off0000721b.bin
18034dc8c8db59e8cbe1802af7db0aa8aa68eeb5d84e9c2d487cc641c12afa20
pdf-font-stream PDF embedded font (sfnt) at offset 0x721B 5360 bytes
font_01_sfnt_off00008473.bin
a7f326357e65b6fc6673a611ea1bf8fddb6d9040cee585a1124edc8b460cc227
pdf-font-stream PDF embedded font (sfnt) at offset 0x8473 10472 bytes