Malicious PDF — malware analysis report

Static analysis result for SHA-256 81e907cb79be7aea…

MALICIOUS

PDF

41.0 KB Created: 2020-08-12 08:16:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 57a91d9b01d56eb93b26c6dbc56e6706 SHA-1: d35c2dcefcdf73f695388959b20add653fe2480b SHA-256: 81e907cb79be7aeaf6df3941336469d4755e7d73d2037a31eccb97e421add553
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded links, many of which point to Shopify domains hosting other PDFs, suggesting a link farm or SEO poisoning attempt. One of the primary links, https://ttraff.cc/wb?keyword=sejarah%20kacang%20kedelai%20pdf, is identified as a malicious redirector. The document body, though heavily obfuscated, contains references to the topic and the tool used to generate the PDF, wkhtmltopdf.

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.cc/wb?keyword=sejarah%20kacang%20kedelai%20pdf
    • http://files.pre-protein.com/uploads/1/3/2/7/132710690/nuziwedunino-fonusozudineve.pdf
    • http://jowolaza.turnerintottenham.uk/uploads/1/3/2/6/132680813/5902257.pdf
    • http://pirupi.christopherbmooneystudios.com/uploads/1/3/0/8/130874359/jibovawupor.pdf
    • http://files.mrsferrell.com/uploads/1/3/1/8/131856040/cd6bb71f1db.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0435/3762/9348/files/pawogapudozinigevu.pdf
    • https://cdn.shopify.com/s/files/1/0432/9888/1704/files/73748858072.pdf
    • https://cdn.shopify.com/s/files/1/0432/0146/2436/files/2889921140.pdf
    • https://cdn.shopify.com/s/files/1/0429/3240/4380/files/70290517985.pdf
    • https://cdn.shopify.com/s/files/1/0439/2806/0059/files/dupazase.pdf
    • https://cdn.shopify.com/s/files/1/0433/6284/4837/files/add_page_break_in_jspdf.pdf
    • https://cdn.shopify.com/s/files/1/0437/6172/9685/files/13362357736.pdf
    • https://cdn.shopify.com/s/files/1/0431/6538/4866/files/84664241167.pdf
    • https://cdn.shopify.com/s/files/1/0437/6212/2903/files/janopi.pdf
    • https://cdn.shopify.com/s/files/1/0429/2201/6934/files/zakilaga.pdf
    • https://cdn.shopify.com/s/files/1/0430/6042/8962/files/25956809953.pdf
    • https://cdn.shopify.com/s/files/1/0432/5313/7576/files/85249619280.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_off0000625c.bin
7706c33c832f95d748c81627b93ba79fa4c635573e3293c2ab78e46721888e7a
pdf-font-stream PDF embedded font (sfnt) at offset 0x625C 5480 bytes
font_01_sfnt_off000074fb.bin
81d4b30bec4caa3d7d29cfe0e1df2c606ec03b1076f67874e145f3c4c0bca040
pdf-font-stream PDF embedded font (sfnt) at offset 0x74FB 10020 bytes