Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4bfd17a4b364349…

MALICIOUS

PDF

47.0 KB Created: 2020-07-16 06:15:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-07
MD5: 3855754bfcadfe7e8c11cf9bcfc523ad SHA-1: c19db72782a2ae4506a91ea6c40ed31e1e239d9d SHA-256: f4bfd17a4b364349d7504c27467c318f64e78feeb3a610eff93e869d03bd71ff
194 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to external files and appear to be part of an SEO poisoning or link farm strategy. One critical heuristic identified a link to known malicious redirector infrastructure. The ML classifier strongly indicated maliciousness. No scripts were extracted, and the document body was heavily obfuscated.

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=manual%20of%20geometric%20design%20standards%20for%20canadian%20roads In PDF document text
    • http://files.friendsoftimbercrest.org/uploads/1/3/2/6/132681757/sexiwebadega.pdfIn PDF document text
    • http://files.microedmspecializedproductionmachines.com/uploads/1/3/1/4/131437064/3403667.pdfIn PDF document text
    • http://files.sardishenderson.com/uploads/1/3/1/3/131398148/sogalozigek-galop-babasunav.pdfIn PDF document text
    • http://files.htagmedical.com/uploads/1/3/0/8/130813118/naduwaj.pdfIn PDF document text
    • http://files.figureitoutct.com/uploads/1/3/2/6/132682030/01760e9.pdfIn PDF document text
    • http://files.mcideative.com/uploads/1/3/1/4/131408371/6732529.pdfIn PDF document text
    • http://files.alissabethphoto.com/uploads/1/3/2/3/132303282/biriwu.pdfIn PDF document text
    • http://files.newwavevolleyballclub.com/uploads/1/3/1/4/131437147/gisaki.pdfIn PDF document text
    • http://files.aprautobodys.com/uploads/1/3/1/4/131453084/nivumowalikuxim_fesatux_gaxiverib.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://vorelav760549551.files.wordpress.com/2020/07/xoboxokaxog.pdfIn PDF document text
    • https://daxazajebu.files.wordpress.com/2020/07/newokod.pdfIn PDF document text
    • https://dokuwedefef.files.wordpress.com/2020/07/46669976982.pdfIn PDF document text
    • https://zimorujiwek.files.wordpress.com/2020/07/84204790737.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/4505/1797/files/49867915344.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0429/8581/6218/files/12849615967.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/28650507632.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/3006/8894/files/40316065233.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/6971/9196/files/surimo.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/dipipopiluniwewikojidil.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/7371/5880/files/lerekibagomufaxogizesev.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_off000078e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x78E9 5228 bytes
SHA-256: 9816356650e546c6c7c581b5cf49eeb7b52ef25e83aa16a316698c66ed3d7501
font_01_sfnt_off00008a9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8A9A 10452 bytes
SHA-256: b99e6e7eef0d3eb0cd410001e270a4047f2841c532ecae2a274735b8ffd5afff