Malicious PDF — malware analysis report

Static analysis result for SHA-256 5fe438da60e7d070…

MALICIOUS

PDF

36.1 KB Created: 2020-08-16 14:56:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ca69b10a9b8e65764bf94d30d1d6d90a SHA-1: 61e6c73c51da4db63e7711f676064abbd0687207 SHA-256: 5fe438da60e7d070d72a5911831ccab55ff3f2bda3f607024a801e43bd7cc2a7
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a large number of embedded links, with a critical heuristic firing for PDF_SEO_LINK_FARM indicating a link farm. One of these links, 'https://ttraff.ru/pify?keyword=contraction+apostrophe+worksheet+ks2', is flagged as a known malicious redirector. The ML classifier also strongly indicated maliciousness. The document body, though heavily obfuscated, contains references to these URLs, suggesting an attempt to lure users or manipulate search results.

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/pify?keyword=contraction+apostrophe+worksheet+ks2
    • http://nurepom.theweddingcelebrantperth.com/uploads/1/3/0/8/130814124/ca9c01a0cee66.pdf
    • http://files.dpcmb.com/uploads/1/3/2/7/132740536/832028.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0427/5470/3526/files/nokuma.pdf
    • https://cdn.shopify.com/s/files/1/0447/9080/8727/files/maborofosafudofe.pdf
    • https://cdn.shopify.com/s/files/1/0437/3279/5541/files/osu_skins_download.pdf
    • https://cdn.shopify.com/s/files/1/0429/0193/0143/files/wopagosaxi.pdf
    • https://cdn.shopify.com/s/files/1/0437/6897/1418/files/razixepuwenusowumok.pdf
    • https://cdn.shopify.com/s/files/1/0439/1639/4648/files/jajopipuvudinerudivetak.pdf
    • https://cdn.shopify.com/s/files/1/0435/0004/4454/files/ccdmd_figures_de_style.pdf
    • https://cdn.shopify.com/s/files/1/0440/9550/4536/files/29443237056.pdf
    • https://cdn.shopify.com/s/files/1/0429/3751/6191/files/jugopara.pdf
    • https://cdn.shopify.com/s/files/1/0428/8797/0975/files/83933693617.pdf
    • https://cdn.shopify.com/s/files/1/0435/3638/4149/files/xevotiwatavixosok.pdf
    • https://cdn.shopify.com/s/files/1/0428/6545/9366/files/41979390004.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_off0000511a.bin
0188c1d20ef483459e543ac7f50792476b0aa588f066780d89f2bd5d23ec7d2d
pdf-font-stream PDF embedded font (sfnt) at offset 0x511A 5184 bytes
font_01_sfnt_off000062c3.bin
8b8f1d6159b62eb9dfd8abee34ca8e0ba31c30ebff5ecc34aa974d80f1c608d4
pdf-font-stream PDF embedded font (sfnt) at offset 0x62C3 9552 bytes