Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9631ab8624cb4a2…

MALICIOUS

PDF

35.6 KB Created: 2020-08-29 17:01:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 299bfe86019f94e926daa7c02d5cc9c2 SHA-1: 147fb33d258b0c787e1cd106cc4530cf02335d02 SHA-256: b9631ab8624cb4a2df436356a122562b925b5c48354f05621f5ed74c425d0e63
154 Risk Score

Malware Insights

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

The PDF contains a clear lure related to 'American standard aluminum i beam section properties' which is directly linked to a malicious redirector URL. The PDF_MALICIOUS_REDIRECTOR_LINK heuristic and the embedded URL confirm this malicious intent. The ML classifier also strongly flagged this PDF as malicious. The document body, though heavily obfuscated, contains the malicious URL and references to other PDF files, suggesting a link farm or redirection strategy.

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=american+standard+aluminum+i+beam+section+properties
    • https://static.usrfiles.com/ugd/b8c837_09a1505ba1864445ae4780b5e3ee6aca.pdf
    • https://static.usrfiles.com/ugd/b8c837_9b8b240113f84047861855218c3ba26b.pdf
    • https://static.usrfiles.com/ugd/b8c837_a8f2906ae8a04caa8d393c15974df4cc.pdf
    • https://static.usrfiles.com/ugd/b8c837_bf257bcf4967410988f926d4b61bbb70.pdf
    • https://static.usrfiles.com/ugd/b8c837_a817384f4a3c4bf39c1c9ee3421b6721.pdf
    • https://static.usrfiles.com/ugd/b8c837_8892ecd23144482e8596fe79f68ec74a.pdf
    • https://static.usrfiles.com/ugd/b8c837_5ee0e4978d2f4d1aa929704d3dc48fbb.pdf
    • https://static.usrfiles.com/ugd/b8c837_2c3ccf94e199499b9bd50393b5a930bd.pdf
    • https://static.usrfiles.com/ugd/b8c837_c8ec1c93e2124960808ea6b7f82222e0.pdf
    • https://cdn.shopify.com/s/files/1/0431/9641/6157/files/lotiwaguvaludapavivo.pdf
    • https://cdn.shopify.com/s/files/1/0432/3196/9438/files/wutakulo.pdf
    • https://cdn.shopify.com/s/files/1/0461/9114/9214/files/ravudekatebipidelutuze.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/fatexuxutul.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_off00004aa7.bin
b81ab27ce17197fc41ea15c7c225b026dbd1c11be45bbd1130c88e131e6dae5f
pdf-font-stream PDF embedded font (sfnt) at offset 0x4AA7 5348 bytes
font_01_sfnt_off00005ca0.bin
9e364f9129226a5d73f0cea4e53fea0141f684b5ad0736bf20b8d2e887a9f45c
pdf-font-stream PDF embedded font (sfnt) at offset 0x5CA0 10196 bytes