Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ff3ec149f155195…

MALICIOUS

PDF

46.1 KB Created: 2020-07-29 14:22:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d76bb3ffcc45109f650f98d5f54fa823 SHA-1: 2364e7499fa4b6ec1707fdfba00c808fa9cabf77 SHA-256: 4ff3ec149f1551957b1c2dec526610ddd549d92ad05a575e3100595b5d5fe896
152 Risk Score

Malware Insights

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

The PDF file contains multiple embedded links, with one specifically pointing to a known malicious redirector. The document body, though heavily obfuscated, suggests a lure related to 'nursery rhymes for preschool pdf'. The presence of numerous external links, including a link farm, indicates a phishing or redirection attempt. The ML classifier strongly flagged this PDF as malicious.

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=nursery+rhymes+for+preschool+pdf
    • http://files.livingmovement.com/uploads/1/3/1/3/131383305/6139948.pdf
    • http://files.form100consulting.com/uploads/1/3/2/7/132710783/bobaruzo.pdf
    • http://files.97litefm.com/uploads/1/3/2/7/132741375/bc0b1b1493fc.pdf
    • https://cdn.shopify.com/s/files/1/0432/2341/6987/files/94106954968.pdf
    • https://cdn.shopify.com/s/files/1/0434/6960/2981/files/62808699842.pdf
    • https://cdn.shopify.com/s/files/1/0430/5806/9655/files/54097764088.pdf
    • https://cdn.shopify.com/s/files/1/0431/4952/5156/files/88264452953.pdf
    • https://cdn.shopify.com/s/files/1/0433/6310/6968/files/pokibegutizobo.pdf
    • https://cdn.shopify.com/s/files/1/0432/5575/9011/files/72954994101.pdf
    • https://cdn.shopify.com/s/files/1/0430/0659/1127/files/redufapunafunufuvutuki.pdf
    • https://cdn.shopify.com/s/files/1/0430/3765/5193/files/53960575807.pdf
    • https://cdn.shopify.com/s/files/1/0432/4907/4336/files/purekawe.pdf
    • https://cdn.shopify.com/s/files/1/0437/7378/8321/files/78881887937.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_off000076f7.bin
26e2158e625f10f16ecab527e8749d1cc79f93fa7a85060e3de4fa1db3d685c5
pdf-font-stream PDF embedded font (sfnt) at offset 0x76F7 4904 bytes
font_01_sfnt_off000087b3.bin
9f34d65725499ea033e5f151d0a6cd4e5187460e99f1692a39d84986caacbc5f
pdf-font-stream PDF embedded font (sfnt) at offset 0x87B3 10392 bytes