Malicious PDF — malware analysis report

Static analysis result for SHA-256 cfb853604ccbb130…

MALICIOUS

PDF

42.6 KB Created: 2020-08-24 20:39:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2c2c9b10104b8619d8ace81f64a6af2d SHA-1: 6f0efaf778da52057591363341e35881f543be5f SHA-256: cfb853604ccbb1303a8aef2322afaf86c65b465543dd768045eef568d9b8b09b
154 Risk Score

Malware Insights

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

The PDF contains a significant number of embedded links, with a critical heuristic firing for PDF_SEO_LINK_FARM indicating a link farm strategy. One of these links, https://ttraff.cc/pify?keyword=i+can+read+worksheets, is flagged as a malicious redirector. The document body, though heavily obfuscated, contains text related to reading worksheets and references the wkhtmltopdf tool, suggesting a lure. The ML classifier also strongly indicated maliciousness.

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/pify?keyword=i+can+read+worksheets
    • http://navomuner.newmorningacu.com/uploads/1/3/1/6/131606289/60af981a7d2b133.pdf
    • http://fubivare.skateteamindy.com/uploads/1/3/2/3/132303093/f6d1d9cb9afd4be.pdf
    • http://files.jennaleeneff.com/uploads/1/3/0/8/130813846/navalifusijazolunu.pdf
    • http://mepiri.riverbottomstockdogs.com/uploads/1/3/0/7/130739625/5803884.pdf
    • https://cdn.shopify.com/s/files/1/0431/2681/6932/files/kuwulo.pdf
    • https://cdn.shopify.com/s/files/1/0434/0930/9854/files/19621349879.pdf
    • https://cdn.shopify.com/s/files/1/0431/4962/3462/files/60825182479.pdf
    • https://cdn.shopify.com/s/files/1/0431/8851/9080/files/wumukogonuluvabe.pdf
    • https://cdn.shopify.com/s/files/1/0427/5650/5756/files/aspirantszone_english.pdf
    • https://cdn.shopify.com/s/files/1/0437/1575/6181/files/66158170359.pdf
    • https://cdn.shopify.com/s/files/1/0429/5085/2762/files/11758288836.pdf
    • https://cdn.shopify.com/s/files/1/0437/2201/4871/files/mujir.pdf
    • https://cdn.shopify.com/s/files/1/0430/4096/4759/files/3893113624.pdf
    • https://cdn.shopify.com/s/files/1/0433/4583/8239/files/recognition_certificate_template_free.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_off00006868.bin
93348e0e0dbd42f2641e12ee4a813de5bf48b6fc48c5c778bdeb0cdd2db661d7
pdf-font-stream PDF embedded font (sfnt) at offset 0x6868 5088 bytes
font_01_sfnt_off000079bb.bin
c45f36faa00ced1ef5b48db9d4b11f3da1d4bff46006011bd4bbe94bac155482
pdf-font-stream PDF embedded font (sfnt) at offset 0x79BB 10748 bytes