Malicious PDF — malware analysis report

Static analysis result for SHA-256 81700ed972368ce1…

MALICIOUS

PDF

35.9 KB Created: 2020-08-06 05:35:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2a409ba23bc487526db9ed07e27bb70b SHA-1: ab5a1e70fdec4e5f4a4cd4810c7cf56c463b0bda SHA-256: 81700ed972368ce12a3d39d5c6a4b3f565d8f4be2bca52b1e08c90a0361a8cbb
154 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with a critical heuristic firing for a malicious redirector. The document body, though heavily obfuscated, contains text related to 'ocr a level biology textbook answers pdf' and includes the primary malicious URL. This suggests a lure to a malicious site disguised as a search result or document repository. No scripts were extracted, limiting the analysis of further payload delivery.

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/wb?keyword=ocr%20a%20level%20biology%20textbook%20answers%20pdf
    • http://files.dndamsels.com/uploads/1/3/0/7/130775551/3863589.pdf
    • http://files.mentalhealthjunkie.com/uploads/1/3/1/4/131407183/670c2.pdf
    • http://files.glenburniequicktaxi.com/uploads/1/3/0/7/130776413/zisivunu_pubifiz.pdf
    • https://cdn.shopify.com/s/files/1/0433/4750/9416/files/bojibujujiwu.pdf
    • https://cdn.shopify.com/s/files/1/0434/5154/7800/files/tejiwulabi.pdf
    • https://cdn.shopify.com/s/files/1/0436/2331/7662/files/dutubekerivasedulare.pdf
    • https://cdn.shopify.com/s/files/1/0433/4557/6088/files/zopebaxixatewoxekiburuzo.pdf
    • https://cdn.shopify.com/s/files/1/0430/9201/7305/files/91106021931.pdf
    • https://cdn.shopify.com/s/files/1/0438/8388/8808/files/marc_benioff_book_behind_the_cloud.pdf
    • https://cdn.shopify.com/s/files/1/0428/0742/7238/files/fodozetafazitajurozibep.pdf
    • https://cdn.shopify.com/s/files/1/0433/2378/5370/files/lofegugegedumixujuzedo.pdf
    • https://cdn.shopify.com/s/files/1/0435/5896/1315/files/mojamige.pdf
    • https://cdn.shopify.com/s/files/1/0440/8626/3960/files/markdown_blank_line.pdf
    • https://cdn.shopify.com/s/files/1/0428/6477/1238/files/math_algebra_rules_pdf.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_off000040df.bin
5fcaa28ecf3abe1e0ab1256028727d0769342bfb83f2a8694043a42774d4a500
pdf-font-stream PDF embedded font (sfnt) at offset 0x40DF 5664 bytes
font_01_sfnt_off0000544d.bin
fed8916ca35bbfd4caf27e07d5a9884ce0194d9f6e8414f8e72e6eaf2612873f
pdf-font-stream PDF embedded font (sfnt) at offset 0x544D 9012 bytes
font_02_sfnt_off0000730b.bin
ad623bc7c681097dfa1224999cf6cc6072d3ca9a137655dc1129b0261f0b357c
pdf-font-stream PDF embedded font (sfnt) at offset 0x730B 4324 bytes