Malicious PDF — malware analysis report

Static analysis result for SHA-256 9fc8f97cb4cc1387…

MALICIOUS

PDF

48.9 KB Created: 2020-07-08 16:08:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2020-08-25
MD5: 9e628d49d039652911c32711dfe58e52 SHA-1: 098b1ca12761dedd6659a8524150c93cbee0933e SHA-256: 9fc8f97cb4cc13879daf45914f8db28731201e070794643d8307855b3d402fd7
184 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, including a critical redirector link to ttraff.ru and a large number of links to external PDF files hosted on various domains, indicative of an SEO link farm. The ML classifier also strongly flagged this PDF as malicious. The document body, though heavily obfuscated, contains the title 'Using inequality signs worksheet' and the malicious URLs, suggesting a lure to drive traffic to potentially malicious or phishing content.

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.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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=using%20inequality%20signs%20worksheet In PDF document text
    • http://files.authorrebeccaarogers.com/uploads/1/3/1/6/131637034/wakobobo_jujorufaxeso_puxul.pdfIn PDF document text
    • http://files.psychometricdynamics.com/uploads/1/3/1/0/131070116/9284285.pdfIn PDF document text
    • http://files.jessicaraeanderson.com/uploads/1/3/1/0/131070379/9611647.pdfIn PDF document text
    • http://files.suncoastsoul.com/uploads/1/3/1/3/131379612/baretanemomimu.pdfIn PDF document text
    • http://files.bodyshapeaesthetics.com/uploads/1/3/0/7/130739780/gofevab_xemamebirelagek.pdfIn PDF document text
    • http://files.unlawfullytasty.com/uploads/1/3/1/3/131379951/taxujuniwiwup-dijefumuwepu.pdfIn PDF document text
    • http://files.fnaq.org/uploads/1/3/0/9/130969944/nivubuluro.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://xevesir.files.wordpress.com/2020/07/34958209719.pdfIn PDF document text
    • https://wikemifap.files.wordpress.com/2020/07/89078806211.pdfIn PDF document text
    • https://movulimisulu.files.wordpress.com/2020/07/29795455472.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_off00007464.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7464 5204 bytes
SHA-256: c1f4102451fbf75e6ff47443449515f391fdab7ad2b7657fb488f87a06f8cac4
font_01_sfnt_off00008618.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x8618 15124 bytes
SHA-256: 3915bf9c14e4d3f0dc172b2c9db1a43fe76b0a98eb4438c00b1c5c3e4182f321