Malicious PDF — malware analysis report

Static analysis result for SHA-256 c89c89fb7db8e0bf…

MALICIOUS

PDF

92.0 KB Created: 2020-07-21 14:40:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-09-04
MD5: 609227589f72651ed6f31be1be7110d5 SHA-1: 1e906d4120eec953b76aaef8f03246887b19482f SHA-256: c89c89fb7db8e0bf30189587df3c965abdc7f76cb889522e5c528bd469e99032
194 Risk Score

Malware Insights

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

The PDF contains multiple embedded links, with one critical heuristic identifying a link to a known malicious redirector. The document body, though heavily obfuscated, suggests a lure related to an 'entropy and gibbs free energy worksheet'. The presence of numerous external PDF links, many hosted on cdn.shopify.com, indicates a link farm strategy to obscure the ultimate malicious destination. The primary malicious IOC is the redirector URL.

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.com/wb?keyword=entropy%20and%20gibbs%20free%20energy%20worksheet In PDF document text
    • http://files.rnshomerenovations.com/uploads/1/3/0/7/130776110/vudiser.pdfIn PDF document text
    • http://files.sophialatrell.com/uploads/1/3/0/7/130775825/kumidofu_wirojiped_tuxexagidoresos_fiwed.pdfIn PDF document text
    • http://files.npanglers.com/uploads/1/3/1/4/131437822/nuvujijoromikil.pdfIn PDF document text
    • http://files.mymonarchs.com/uploads/1/3/1/3/131383924/raxaruti.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/1/0427/7728/0671/files/zubuzalatukajijemuz.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/0477/3031/files/tududevafiboli.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0438/8637/9160/files/wusovelabixokuvode.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0436/5778/9605/files/vuneko.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/mowojemabedeju.pdfIn PDF document text
    • https://budixifanedo.files.wordpress.com/2020/06/vutozi.pdfIn PDF document text
    • https://karasakijapi.files.wordpress.com/2020/07/lirowajidupelegojeziz.pdfIn PDF document text
    • https://sawaruvenuk.files.wordpress.com/2020/07/46739710927.pdfIn PDF document text
    • https://kixavokof.files.wordpress.com/2020/07/75758102412.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0432/4674/7803/files/nibinilawinulizuju.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/8266/9461/files/tigemiwo.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/43778875991.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/4827/9957/files/butuxavibuxarazisub.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/5735/6710/files/19487323028.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0429/9620/3679/files/rirevewijiwujexoju.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/8678/2369/files/rasezimutususozadalowe.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010487.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10487 5416 bytes
SHA-256: 9fabef0793c1b1d09cb26b573e2d176ecdfec395c8970a53265a2e268a4017da
font_01_sfnt_off00011700.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11700 17340 bytes
SHA-256: ba09c43ced9405279fd71900b2f6de3eb6e6fdbc3fa67aa3d33f47ab94b1fc52
font_02_sfnt_off00014d08.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14D08 16168 bytes
SHA-256: 50e08210591ebecb2f48b31358b4da406fa7777b33a5f5891cb3e672ae20b528