Malicious PDF — malware analysis report

Static analysis result for SHA-256 b40f34878c5ab77c…

MALICIOUS

PDF

42.1 KB Created: 2020-07-10 01:09:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-08-10
MD5: 037d47be2485a0e4796c45f28f6cd4bd SHA-1: cbe7f731580b85fd38094bd46b51cf8cea959aac SHA-256: b40f34878c5ab77c57329dd9c3c58880b8b9948fef7f6f099be037d996dfd313
194 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, including a redirector to 'ttraff.com' and a large number of links to PDF files hosted on various domains, indicative of a link farm. The document body, though partially corrupted, suggests a lure related to 'Present continuous exercises worksheet'. The ML classifier strongly flagged this PDF as malicious, and the presence of a malicious redirector link confirms its intent to lead users to harmful content. No scripts were extracted from this sample.

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=present%20continuous%20exercises%20worksheet In PDF document text
    • http://files.wellspringscelbridge.com/uploads/1/3/1/6/131636995/4450282.pdfIn PDF document text
    • http://files.thegirlsfromguantanamo.com/uploads/1/3/2/6/132681938/2217839fd6588e.pdfIn PDF document text
    • http://files.knightsknews.com/uploads/1/3/0/9/130969987/nezazemesozafejas.pdfIn PDF document text
    • http://files.pennsylvaniaeitc.org/uploads/1/3/0/9/130969085/272e8d61372.pdfIn PDF document text
    • http://files.peterarmstrong225.net/uploads/1/3/2/8/132815342/dae4c49fd7.pdfIn PDF document text
    • http://files.biophysical-ecology.com/uploads/1/3/1/4/131406356/xivut_girusidusowele_finusagon.pdfIn PDF document text
    • http://files.travistagpta.org/uploads/1/3/2/6/132696063/159d094eebc4b5.pdfIn PDF document text
    • http://files.autumnskinner.com/uploads/1/3/1/4/131453284/9274844.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://xaxuxite.files.wordpress.com/2020/06/72685303088.pdfIn PDF document text
    • https://sobapawesug.files.wordpress.com/2020/07/25828720684.pdfIn PDF document text
    • https://xibupaxip.files.wordpress.com/2020/07/15124027214.pdfIn PDF document text
    • https://jokurana.files.wordpress.com/2020/06/bodotarenubokozeferuti.pdfIn PDF document text
    • https://sazubafuzute.files.wordpress.com/2020/07/lujemaxeteluz.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/wudusojixidotivage.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/5555796470.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/sotuxinonuwirumedubisaz.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/65294746239.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/72593533024.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/parisibudipaxetiwori.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/58933331969.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_off00006814.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6814 4752 bytes
SHA-256: 48ad87a3e1492bef56bf0a71d9c3050e222843aceb87762e2873cc6e828aa68b
font_01_sfnt_off00007843.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7843 10224 bytes
SHA-256: 0bd9d529ead054487d5a4fc1de94e271e848c9581fd124bc355bddd60a680fa2