Malicious PDF — malware analysis report

Static analysis result for SHA-256 8fc0a6a681771490…

MALICIOUS

PDF

49.7 KB Created: 2020-07-26 05:14:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-04
MD5: 2963f60cc55807ca4d56915bb8918ef4 SHA-1: df8c5261accf168e2374e70348ed6202b749ddd5 SHA-256: 8fc0a6a6817714900418d7ca3e93ba87b2024b42ef130cfc68c85d36dba2ffa5
194 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, with one pointing to a known malicious redirector. The ML classifier also flagged this PDF with high confidence. The document body, though heavily obfuscated, appears to be related to an educational worksheet, which is a common lure for phishing or malware delivery. The presence of numerous links, including those hosted on cdn.shopify.com, suggests an attempt to leverage SEO poisoning to drive traffic to malicious sites.

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.ru/wb?keyword=identifying%20and%20correcting%20sentence%20fragments%20worksheet In PDF document text
    • http://files.hiswillnotmine.org/uploads/1/3/0/7/130775588/4bc88.pdfIn PDF document text
    • http://files.tedxunionvillehs.com/uploads/1/3/0/7/130740480/662c2982.pdfIn PDF document text
    • http://files.stvincentequestrian.org/uploads/1/3/2/6/132695216/7280773.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/1/0430/8575/8618/files/sewedubuxazosivusovaki.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0435/3956/2651/files/68607714218.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/3730/2679/files/60574541106.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/7289/6672/files/18296692743.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/4058/7431/files/juvama.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0429/0979/4463/files/pikuxilamutumijenex.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0436/4884/3934/files/93280212876.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/1630/6344/files/venerotumedunaludotu.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/84407481133.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/sujaxitedidubabupopivup.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/8436/5476/files/joxikejex.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/1758/5308/files/64321879134.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0429/6825/2565/files/vadajixotunimotunolizo.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/2872/5405/files/xoten.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_off000083a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x83A9 5388 bytes
SHA-256: 0b42adbbbb9bc9f895e10e64950f647b9dcdc1fc34990b5a9433660dfcb6f48e
font_01_sfnt_off000095dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x95DD 10268 bytes
SHA-256: ad233be6a21580ebf0be413725d84e3b3136becf52d7a82ed177f9b31ce035a7