Malicious PDF — malware analysis report

Static analysis result for SHA-256 f375fdfa6d3b8816…

MALICIOUS

PDF

39.2 KB Created: 2020-07-14 06:45:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-24
MD5: e24748363cb564736012ce09a1f0270f SHA-1: ce11674d7b3c60a6dd0eb5cfd0193b7cea9566e3 SHA-256: f375fdfa6d3b8816be076e1f0a69a9e72675b2c98c335b45fc5e7641b25582ea
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link T1059.001 PowerShell

This PDF file was flagged as malicious by a machine learning classifier and contains multiple heuristics indicating malicious intent. It includes a link to a known malicious redirector and a large number of links to external PDFs, suggesting a link farm designed to manipulate search engine results or distribute malware. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool sometimes used to create malicious documents.

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=past%20simple%20past%20perfect%20worksheet%20pdf In PDF document text
    • http://files.clubgymnastica.com/uploads/1/3/2/7/132712199/971160.pdfIn PDF document text
    • http://files.supertomcustoms.com/uploads/1/3/0/7/130739099/ravezoj.pdfIn PDF document text
    • http://files.cisenoughisenough.org/uploads/1/3/2/6/132681884/koxumamafedazi.pdfIn PDF document text
    • http://files.teethwhiteningmonterey.com/uploads/1/3/2/6/132696335/5cde3.pdfIn PDF document text
    • http://files.inlandmetalcrafts.com/uploads/1/3/0/9/130969899/e6edfc.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/1/0431/5430/9280/files/vebikeve.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0429/8119/5927/files/lawafokeriwigarososop.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0434/5161/3334/files/noxedenotesusi.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/6641/6549/files/34779724370.pdfIn PDF document text
    • https://kuxozuleni.files.wordpress.com/2020/07/4917764484.pdfIn PDF document text
    • https://sufikisakevi956131754.files.wordpress.com/2020/06/zesebuxojugefivon.pdfIn PDF document text
    • https://zadidepetox.files.wordpress.com/2020/06/5729548654.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/8307/1650/files/89957663193.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/7372/3800/files/jixadafat.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/20931566490.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/30740110423.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/0867/2423/files/ziwemikimekodufobeduxawit.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/22584543347.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/4314/4359/files/zozag.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/7096/3350/files/18514420709.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/0092/2261/files/zobesivotepikaxapa.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/13170590630.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_off00005bb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x5BB3 5232 bytes
SHA-256: bdb8140b727ce60ab8aac043bc9eba97f5d1b4aff052eabf44f22285c836d314
font_01_sfnt_off00006d89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6D89 9752 bytes
SHA-256: 0317106ac088e737ce3ce82650a0fa43cc9965ce58d0082b491582aabd2c06c4