Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8361bbaf47de7df…

MALICIOUS

PDF

35.9 KB Created: 2020-08-22 09:22:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d8134f8d6daf8bf8aa2aada00eb4de53 SHA-1: 7a16a10a7e6d9a2afb5b5568447d8d58a766015c SHA-256: b8361bbaf47de7dfb98a1171f689f67ec82d2266ac9f83d4438066e1369d7d57
152 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and contains numerous embedded URLs. One critical heuristic identified it as a PDF link farm, with many links pointing to external PDF files hosted on domains like cdn.shopify.com. Another critical heuristic indicates a link to a known malicious redirector at ttraff.ru. The document body, though heavily obfuscated, contains text related to 'English malayalam dictionary app' and the URLs, suggesting a lure or redirection mechanism.

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=english+malayalam+dictionary+app
    • http://zejafu.folsomepoxy.com/uploads/1/3/1/3/131398252/a1d65967.pdf
    • http://files.citruscountyaudubon.org/uploads/1/3/2/8/132814050/niniresosogur.pdf
    • https://cdn.shopify.com/s/files/1/0434/0485/3406/files/app_center_push_notifications_android.pdf
    • https://cdn.shopify.com/s/files/1/0430/7822/1973/files/24490910629.pdf
    • https://cdn.shopify.com/s/files/1/0432/2626/7816/files/80955173561.pdf
    • https://cdn.shopify.com/s/files/1/0438/2926/4546/files/60997767205.pdf
    • https://cdn.shopify.com/s/files/1/0432/4353/6552/files/86183025980.pdf
    • https://cdn.shopify.com/s/files/1/0432/8649/5397/files/61727521881.pdf
    • https://cdn.shopify.com/s/files/1/0429/7064/4631/files/55155708036.pdf
    • https://cdn.shopify.com/s/files/1/0432/3033/1040/files/aadhar_download_open_password.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/80804151078.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_off00004da5.bin
800a37729a7b898cae8e36582ac6693da4f9aac1e12614e7dddd92c8cc41978f
pdf-font-stream PDF embedded font (sfnt) at offset 0x4DA5 5544 bytes
font_01_sfnt_off00006052.bin
311a5cb013b38f34c465917d178fd7e9ddefa4337120f290f8bf6008cdc2743f
pdf-font-stream PDF embedded font (sfnt) at offset 0x6052 10188 bytes