Malicious PDF — malware analysis report

Static analysis result for SHA-256 64d4a31b731c8a6a…

MALICIOUS

PDF

47.6 KB Created: 2020-07-20 18:48:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-24
MD5: 059ee416ab50064a1ee4b3d37b7f1df9 SHA-1: c3f77d9a97a3a6a89e296f2ae27c4bcb47144c33 SHA-256: 64d4a31b731c8a6aba1f926343b28e932fdf3220ed83cdee9e7a2bf446990d4f
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links to external resources, many of which point to redirectors and SEO link farms, indicating a malicious intent to drive traffic to potentially harmful sites. The ML classifier strongly flagged this PDF as malicious, and heuristics confirm it links to known malicious redirector infrastructure. The document body, though heavily obfuscated, appears to be a lure related to educational worksheets.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • 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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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=100%20times%20tables%20questions%20worksheets In PDF document text
    • http://files.balancedforlifeyoga.com/uploads/1/3/1/3/131380005/satuve_xinesikujesuraj_xewapituboli_movekimowupaw.pdfIn PDF document text
    • http://files.charlesfbond.com/uploads/1/3/1/4/131406153/vifetasiju_kamokek.pdfIn PDF document text
    • http://files.stampexinternational.co.uk/uploads/1/3/0/7/130739383/zozewisibu_danenugoravinas_zibazoned_vinudi.pdfIn PDF document text
    • http://files.ohionursepreceptor.com/uploads/1/3/2/3/132303134/f7272ccb05451f6.pdfIn PDF document text
    • http://files.kekusa.com/uploads/1/3/2/7/132710786/kazal.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/9064/8994/files/tubamizozogusozuborokarer.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0434/9755/4084/files/sizuged.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/7111/1330/files/tetugagemarilipalakit.pdfIn PDF document text
    • https://rolinozopuj.files.wordpress.com/2020/06/wafiruzalanuzumifojeseka.pdfIn PDF document text
    • https://fimesijonoba.files.wordpress.com/2020/06/namevolururomupejixud.pdfIn PDF document text
    • https://lotodirod.files.wordpress.com/2020/07/gobiz.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9868/6119/files/gilodimub.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/0118/4417/files/newizasa.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/4389/8019/files/fogefimewabebixi.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/9085/3531/files/46698098986.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/monazata.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/7567/4024/files/63086526189.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/2630/8510/files/82455675110.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0434/2166/3397/files/49097523626.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/rexalomofovuwazeb.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/7743/5556/files/75502225613.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00007c19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7C19 5328 bytes
SHA-256: cad96b7eecc3702b56ab76e870c09ec53ede01ac8745cf3ca98a6a3683ccfd3d
font_01_sfnt_off00008e0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8E0F 10104 bytes
SHA-256: 3c22824b0e1ecd8c249cd7fe61c1ed836f782b76b7471c5ef084634be6ba4b7f